Best emergency water storage containers for your home

13 May.,2024

 

Best emergency water storage containers for your home

One of the easiest, yet most important things you must do to prepare is store at least two weeks of water in your home. The majority of Americans have less than 12 hours worth of water in their home, yet humans die after just three days without it. We spent 34 hours researching and testing all of the popular small containers to find the best one for emergency water storage. We recommend the Reliance Rhino 5.5 gallon Water Container and Scepter 5 gal Military Water Can .

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These containers are usually one of the first things people buy when starting to take emergency preparedness seriously. That’s because having water stored ahead of time, ready to use, is one of the most impactful things you can do. And it’s cheap and easy!

The key difference between these kinds of smaller jerry cans and larger water tanks/barrels is that they’re small enough for an average adult to carry by hand, on foot, when full of water. Even if you have larger tanks, it’s a great idea to have some of these smaller ones around for when you need to travel for refills, and so on.

Related reviews: Best portable water filters, portable water purifiers, water canteens, and home water filters

Top Pick

Best container for most people:

Reliance Rhino 5.5 Gal Water Container

Toughest container in the middle tier price class. Somewhat stackable for short term storage. Comes with everything you need. Survived our drop and crush tests.

If you want to buy just one type of container to hold your most critical emergency water needs, the 5.5 gallon Reliance Rhino is a great deal. Typically found around $20, it’s reasonably priced and just a few dollars above the more common Aqua-Tainer (our budget pick). That extra money buys a tougher and thicker container that will survive things like earthquakes and accidental drops much better than its cheaper siblings.

The Rhino was one of the easiest to carry among all the containers we tested. It pours well and has a better screw cap for the airflow vent, rather than the cheap push-pin style plugs found on many other similarly-priced containers.

The Rhino also has a sorta-stackable feature built into the side walls — you wouldn’t want to store them stacked for the long term, and we found one of the side walls will bow out a little over time, but it’s a handy feature for short term use (like moving them in your car). Note that it’s not unusual for any of the products in this $10-25 price tier to leak a little around the cap if you hold the container upside down or on its side. You’ll need to upgrade if you want better manufacturing quality…

Upgrade

Best overall can:

Scepter 5 Gal Military Water Can

The best overall water can we've ever tested. Built tough. Military tested features. Very large fill hole, secondary spout hole, screw top airflow vent. Nice spigot accessories.

Our upgrade pick is the Scepter 5 gallon Military Water Can. They are the toughest container over five gallons we tested. The MWCs have military tested and practical features like a giant 4” filling hole, a locking ring to prevent accidental loosening, a smaller 1” pour spout with no moving or reversible parts, and molded stability feet.

At around $50 (after shipping) they are twice as expensive as the Reliance Rhino and three times as expensive as the budget Reliance Aqua-Tainer pick — but we think it’s a very worthy upgrade that will serve you well in a crisis and last for 20 years, saving you money in the long run. We are now personally using these Scepter WMCs in our preps.

Budget

Cheapest way to store enough water:

Reliance Aqua-Tainer 7 Gal

Good value in a cheaper package. Stores more water than normal for its price class, but may be too heavy for some. Comes with everything you need. Not as durable and may crack, but does have five year warranty.

Our budget pick is the 7 gallon Reliance Aqua-Tainer. It’s a popular option found in many stores for around $20. The cheaper cost means less durable plastic that is prone to denting and cracking, but dollar-for-dollar we were impressed with how well Reliance made this affordable option.

If you’re on a tight budget, buying two of these per person is the cheapest way to get your two weeks of water supply covered. Their cube shape stores well and sits nicely on a tabletop edge with an included and reversible bottom side water spigot. It didn’t pass our drop and crush tests, but should survive gentle in-home use.

Stackable

If you are space constrained:

WaterBrick 3.5 Gal

Ultra-stackable up to five levels high. Mediocre caps and spigots, but the best way to store water in tight spaces. Very durable, you can even use them as tables or defensive walls. Expensive.

Our space-saver pick is the WaterBrick. If your primary goal is to fit the most water in the smallest space possible, these ultra-stackable and durable water containers are your best bet. They are expensive — a set of four, or 14 gallons, will cost you around two times as much as alternatives, including the additional water spigot and cap you must buy. If you’re buying for two people, the 8 Pack might be a better deal. We found them a little disappointing in terms of storing and using water, but they easily passed our durability tests and can fit in random pockets of space around your home.

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Best overall bang for your buck: mix multiple containers

Because you need at least 15 gallons per person and most households will need 30-45 gallons total, you’ll need to buy multiple 5-7 gallon containers.

Our recommendation for best overall container will work great if you simply buy multiple of that product. That was part of our criteria for picking the best container — it had to be good enough if it’s the only type you buy.

But some containers had features that worked well in specific situations or were great budget options that didn’t work well in every situation.

For example, the popular Reliance Aqua-Tainers are reasonably priced at $20 and do a decent job. They were not good enough to be our main pick, mostly because they’re made of thinner plastic that dings and cracks more easily than the main choices. So they might work fine if they are stationary in your home and won’t take much abuse. Plus they have an advantage over the jerry cans because they sit nicely on the edge of a countertop with a spigot on the bottom.

Our ideal mix for a home of two people:

  • Two Military Water Cans with the extra spigot hose. 10 gallons total.
  • Two Reliance Rhinos. 11 gallons total.
  • One Reliance Aqua-Tainer. 7 gallons.

Best budget mix for a home of two people:

  • Two Reliance Rhinos. 11 gallons total.
  • Three Reliance Aqua-Tainers. 21 gallons total.

If you’re on a budget, try to at least buy one or two of the much more durable Military or Rhino cans. Don’t just buy five of the cheapest product. It’s not worth saving $40 to find out your emergency water has leaked out or is tainted when you need it most. The cheaper options will likely need to be replaced every few years due to cracking, so you’ll end up spending more money in the long run anyway.

Why you should trust us

We spent over 34 hours researching and reviewing this topic, in addition to over ten years of experience with many of these products in both survival and camping use. We reviewed over 20 products and personally bought and tested over 10 containers. The main author has personally researched, bought, installed, and maintained off-the-grid water systems with cisterns up to 2,500 gallons a piece. We use these recommendations in our own homes and because water is so important, we are trusting our family’s lives with these products.

Store a minimum of 15 gallons per person

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The Prepared’s minimum recommendation is two weeks of supplies in your home. The rule of thumb is one gallon of water per person per day. So you need a minimum of about 15 gallons per person.

The old advice of 72 hours worth of supplies has been replaced by the two week recommendation because in real disasters, emergency responders have taken up to 8-9 days to respond to everyone.

You don’t need to look far to see evidence of why this is so important. It might be a situation like Flint, Michigan where people were without clean utility water for multiple months. Or after a disaster like Hurricane Katrina, where FEMA struggled for a full week to get drinkable water to everyone who needed it.

For example, after the 1994 Northridge earthquake in Los Angeles that caused ~$25 billion in damage, 50,000 homes were cut off from water for at least five days. Some estimate that 12,000 homes still didn’t have water almost two weeks later.

Water must be ready to use at all times

Water is so important, you want to cover the minimum two weeks supply without any unnecessary work or risk. Proper emergency water is just there and ready — always.

No searching for water, no filtering, no boiling, no filling the bathtub, no running to the store to buy cartons of bottled water, no depending on the 30 gallons in the water heater. Any extra stuff you have like water filters in your bug out bags, on-site wells, the bathtub, or your long term water purifiers are just bonus backups.

Avoid shortcuts like bottled water, milk jugs, and office jugs

There’s a few areas in prepping where it’s fine to use DIY home remedies and/or rotating stock in order to save some money. Water is not one of them.

Never use a container that held something other than food. If you try and recycle things like milk or juice cartons, even though it’s possible to properly clean out any existing bacteria, you don’t want to run the risk just to save a few dollars in the short term. Besides, even if you were able to totally sanitize something like a milk jug, they are often biodegradable and designed to break down quickly.

Two liter soda bottles are a little better than milk or juice cartons (partly because the acid in soda killed any milk-style cultures), but they still fall short because of being transparent and not very durable. If you must use something off the shelf, try Arizona Green Tea jugs. They are sturdy and semi-opaque.

Many people think about a rotating system, where they buy a carton of bottled water, drink it for daily use, and just keep replenishing the stock so that they always have two weeks worth on hand. Most survival experts and teachers agree that while this sounds nice in theory, real life gets in the way and you could easily get caught off guard without enough water.

Problems with normal bottled water:

  • Essentially a single-use item. You might need to use these water containers for longer than two weeks.
  • Easy to crush / crack / break.
  • Not space efficient. It’s a lot more cumbersome to store 15 gallons of bottled water than 15 gallons in the proper containers reviewed here.
  • Hard to move in bulk. If you needed to suddenly moved 10 gallons to a different location, or take them down to a river to refill, it’s easier to grab and carry two large containers than a bunch of small bottles.
  • It’s more expensive in the long run. Tap water is free.
  • Why waste all that plastic?
  • Shorter shelf life. They have shorter expiration dates and typically don’t have the good chemical treatments that tap water does.

Office jugs (the big upside down ones) have similar problems. They are mostly transparent, hard to handle, and not designed for long term storage or emergencies. What if you don’t have the base part? How do you reseal the jug?

Quick tips on water storage

  • With the right container, water source, and storage, water can safely last 3-5 years — but we recommend rotating it every 2-3 years.
  • Not all plastics are safe for storing water. Look for the number inside the recycle symbol. Plastics 2, 4, and 5 are generally OK for water storage. 1, 3, 6, and 7 are not.
  • Plastic #2, also known as HDPE, is generally considered the best.
  • Plastic can absorb chemicals, so try not to store water containers on cement garage floors or other places where it will contact bad stuff.
  • Light, heat, and bacteria are the enemies of clean water storage.
  • Don’t recycle daily things like soda bottles or milk jugs. If you must, be sure they are properly cleaned beforehand.
  • When water freezes, it expands 10%. If you must store water in a place it might freeze, only fill your containers up ~85%.

How to clean a water container:

  1. Fill it with warm water and a little dish soap. Close cap. Shake. Drain and rinse. This gets the obvious debris out of the can.
  2. Fill it with a quart (about 15 seconds of normal faucet flow) and a teaspoon of unscented household chlorine bleach. Close cap.
  3. Wait 30 seconds. Shake well. Wait 30 seconds again.
  4. Drain and rinse.
  5. Air dry (or fill right away with clean water).

You don’t need to chemically treat water before or after storing

Unless you fear your local utility water has been having Flint-style issues, every modernized water grid treats their water. When it comes out of your tap it already has some chemicals, like chlorine, in small amounts approved by the FDA.

Assuming your container is properly cleaned and stored, you can just fill it with tap water and it will be safe for at least a year.

If you want to err on the side of caution, you can add a little bit of water preserver. We might do a full chemical lab test on water preservers in the future, but for now you can pick up the popular Water Preserver product or just use five drops (1/8th of a teaspoon) of unscented basic household bleach (5.25% sodium hypochlorite) per gallon.

If your water comes from a well or other untested and untreated source, then we do recommend adding the chemical preserver.

Be careful about putting contaminants into the water. Wash your hands before touching the equipment. Wash the lids, caps, spouts, and inside of the container with soap or chlorine.

How we picked

We started by researching as many legitimate product reviews, forum conversations, and guides on water storage as we could find. Combined with personal experience, we defined the most important qualities and what we were and were not looking for.

We searched Amazon, Walmart, REI, Cabelas, and the major prepper ecommerce stores and forums for any relevant products. After reviewing over 20 options online, we picked 10 to test in person:

Pricing, availability, and brands

We noticed inconsistent pricing and availability in the water container category. Manufacturers tell us that large orders from the military and rescue efforts after the 2017 hurricanes and wildfires have created a backlog.

Many of these manufacturers don’t sell directly on major stores like Amazon because the civilian market is not their core focus. So they rely on distributors that can set their own pricing based on demand and supply. We’ve seen that create weird price fluctuations when inventory gets low. For example, the Scepter Military Water Can has been seen on Amazon for as much as twice the MSRP.

When we link you to a store to buy a product, know that we’ve chosen that store because we found them to be the most fair and consistent. In some cases that’s Amazon, and in other cases it can be military sales websites.

There are popular outdoor, camping, or emergency preparedness brands that simply put their sticker on a can and charge you more. Like this Ozark Trail branded container that is just a Reliance Desert Patrol can – you can even see the Reliance name in the product photo.

If you do some quick poking around on Amazon, it seems like Reliance owns the category with their popular Aqua-Tainer and Jumbo-Tainer. Keep in mind that just because something shows up on the first page of Amazon and has ~4.5 star ratings, that doesn’t mean it’s the right choice.

We made an effort to find other brands like Coleman and Igloo, but they were often too hard to find or had incomplete product info.

Other tanks are made for restaurant or industrial use, and may be fine products, but tended to be harder to buy via very old websites with high markups and expensive shipping.

Capacity vs. weight vs. risk: use containers under seven gallons

It’d be nice if you could just buy one 15 or 30 gallon container and be done with it. But for the purposes of short term water needs we only considered containers that held 10 gallons or less. Most containers in this class are either 5, 6, 7, or 10 gallons.

We did this primarily because you might need to move the containers in these short term situations. Maybe you bring it up from your flooded basement, lift it from the ground to a countertop, or carry it to your car to bug out.

A gallon of water weighs over eight pounds. So even a small five gallon container is going to weigh over 40 pounds when full.

A common mistake is looking at a water container and underestimating how heavy it will be. We have found in practice that even seven gallon containers are getting very heavy (~56 pounds) for most people to comfortably move with one hand.

But we did pick a 7 and 10 gallon container to test in person, just to double check the weight issue with a wide range of people.

This also helps reduce the single point of failure risk. If you have three containers of five or six gallons each, and keep one in your pantry, one in your closet, and the other in your garage, it’s more likely that at least one of them would survive something like an earthquake or tornado. Again, when it comes to short term water, we are always overly cautious.

We love larger, longer term water storage containers and will do a full review on them in the future. There are lots of great options, especially in the 55 gallon barrel class. But they serve a very different purpose, and you’re never going to move a 450 pound tank of water.

There were some tempting options, like the 15 gallon water barrel from Emergency Essentials. But 15 gallons would be 125 pounds, so we did not include it in our testing.

Toughness and durability

To make it easy and practical to keep water stored and ready to go for a long time, you shouldn’t have to worry about cheap containers that will crack, dent, leak, or fall apart in something like an earthquake or flood. They also need to be durable enough to handle normal camping-style wear and tear.

We automatically excluded flimsy or collapsable containers. They might be nice for camping, but they are not durable enough for this need. It’s the same reason you should never use milk jugs, since they are designed to break down over time.

The most common issue referenced in Amazon reviews was leaks and cracks. Unfortunately, almost every popular water container in the $10-$50 range has reviews that mention these problems. But we didn’t automatically disqualify them, especially since the next options are more expensive at around $70-130 per container.

Based on past experience, we tried to avoid containers that used the push-plug style cap on the airflow hole. They just don’t hold up as well to frequent use, can be broken off and lost, and are prone to leaks. But for the sake of completeness, we tested some of the most popular containers with this plug.

Ease of storage

Seven gallons, or a week’s worth of water for one person, takes up about a cubic foot. Even if you don’t have a lot of extra storage space in your home, two cubic feet of space for two weeks of water is a reasonable amount to set aside for such an important thing. Two cubic feet is just a few inches larger than an airplane carry-on.

There are a wide range of container types. They were usually either tall and skinny ‘jerry’ cans, cubes, or tall circular tubes.

Some were designed specifically for storing in the bed of a truck or other special situations. We disqualified anything that had such an odd shape they would be difficult or inefficient to store in a normal home – like the cone-bottom tanks that make removing water easy but are impractical for home survival needs.

We love the idea of stackable containers — they (should) add some extra durability and are very space efficient, especially by requiring less floor space through expanding vertically.

Unfortunately, there weren’t that many options for containers that were designed to stack or fit snugly together. The ones that were stackable tended to be much more expensive just for that feature.

In the end, we thought of stackability as a nice to have but not a need to have. Partly because there weren’t any stackable containers that we loved, and partly because the value of stacking got impractical after going two layers high.

Ease of use

You’ll do three main things with a water container: fill it, move it, and remove the water.

Some containers have odd caps that require a special ‘bung’ wrench to open. Others require that you buy extra pieces or special spigots for filling and removing water.

We didn’t automatically disqualify a product for requiring you to buy or use an extra piece, but we did exclude containers that had confusing, proprietary, or easily breakable required pieces.

The best products were simple and could be used without these special tools, so that if you needed to in a crisis you could just unscrew the cap with your hand and get quick access to the water. We often use the “ten year old child” test — if a normal ten year old can’t do it without any help, then it’s no good.

Materials

Plastic is great, but there are some important considerations:

  • Plastic is harder to sanitize than other options.
  • There are many different types of plastic. Some are good for water storage while others are definitely not. Sometimes it’s hard to tell what a product is made of.
  • Plastic can crack easier than other materials.
  • Plastic can absorb bad stuff and leach into the stored liquid.

Many plastics can absorb chemicals and even scents from whatever they touch. For example, if a plastic jug is sitting on a cement basement floor and a bottle of cleaning chemicals spills nearby, those chemicals can be absorbed into the plastic water container.

It works the other way, too. Plastics can leach chemicals out into whatever they’re holding. That’s why people avoid #7 plastics with the BPA chemical, because the BPA can leach out from the plastic into your drinking water.

There is some debate about how realistic this concern is or in what conditions plastic will or won’t absorb bad stuff. Because it was enough of a debate, we erred on the side of caution.

We disqualified any product that wasn’t guaranteed BPA-free or made of food grade materials.

The safest plastic containers to hold water are polyethylene-based plastics, or plastics #1, #2, and #4. All food-grade plastics are made of High-density polyethylene (HDPE) #2. But be careful, because something made out of HDPE #2 might not necessarily be food grade.

There are advantages to materials like glass and stainless steel. For example, glass is easier to decontaminate than plastic. But we think glass containers are too impractical for this situation because they are more likely to break, are much heavier, let more light through, and can be more expensive.

Shelf-life, safety, and container colors

Tap water will be safe in almost any common container after 2-3 months in a dark cool place. But we also care about the shelf-life of the water because it’s impractical to replace your stored water every three to six months. Our goal is to easily keep water safe for at least 12 months and ideally 2-3 years.

Even beyond the normal plastic leaching concerns, the materials and transparency of a container can affect the water inside.

Technically, water never “goes bad.” Water might get stale due to lack of oxygen, but that’s quickly fixed by shaking and swishing it around.

What’s not OK is bacteria growth or contamination. Heat, light, and bacteria are the three enemies of water storage, which is why most serious water storage options use UV-resistant materials and are typically darker solid colors, like the solid blue plastics used in popular 55 gallon water drums.

That’s the same reason why most beer bottles are dark. Light can ruin the taste and shorten the expiration. Fun fact: this is why Corona has trained people through marketing to add a lime to their beer — it’s actually to cover up the bad taste from the clear bottle.

The universal color for potable water is a fresh blue color. Some of the products available use that color for easy identification. All else being equal, we prefer containers in that color, but being blue was not a very important criteria. However, it is important that your potable water containers are clearly labeled so you don’t cross contaminate.

How we tested

Other than just testing the obvious stuff like simple leaks and product quality, we did more rigorous tests to see how well the containers held up to abuse and simulated emergencies in addition to how easy they were to store and use.

Filling and draining

Unfortunately, there is a wide variance in how well different containers do their most important job of receiving and dispensing water. Some had very odd caps, some had caps that could only be sealed once and then had to be replaced, and others have spigots that would clog or fail.

We had a 10 year old, a 17 year old, and two adults try to twist on and off any needed caps and accessories, then do the normal filling and draining cycle, all without any instructions.

Some of the containers had existing product reviews that complained about not draining all of the water without some gymnastics. So we tested how well they drain water in their natural resting position and how easy it was to use one hand to maneuver the container and/or spigot while using the other hand to hold a cup for filling.

Because you don’t want to waste water in an emergency, we tested how easy it was to control how quickly water poured out. This also usually affected how nice the pour was — did it spread or spray, split into two streams, dance around, etc. We tried to find three controllable speeds for each container: a small trickle to fill a shot glass without spilling, an average flow to fill a Nalgene style water bottle, and the maximum flow possible to fill a cooking pot.

Storing

Even though each container isn’t that large, because it’s important that you keep this water in a climate controlled, accessible, and secure area — rather than in the backyard shed that will be frozen for months at a time — we tried to simulate how easy it was to store them in logical places around a house and apartment.

In three different homes, we asked people who weren’t experienced survival planners to store containers wherever they thought it made sense. We observed how logical or frustrating it was and whether a container fit nicely in common areas like a pantry, closet, etc.

Carrying a full container by hand

Since every gallon of water weighs eight pounds and it’s very possible you might need to move the containers during an emergency, we tested how easy it is to carry the fully filled containers with one hand.

We used three different people for these tests: a strong adult man, an adult woman with average fitness, and a teenage boy with average fitness for his age group.

Each person carried each container up a flight of stairs, down a flight of stairs, 100 feet across flat ground, and then loaded it into the trunk of a car. Or they carried it in that order as far as they could. For example, most people couldn’t carry the 7 gallon container through the finish, and no one could complete the 10 gallon one (which did not have a carry handle). There was a rest period between each carry.

Leak tests

After filling and sealing the containers, we laid them flat in a way that put a reasonable amount of internal water pressure against the seals. They sat for three days and we measured any leaks. We then suspended them upside down or in such a way that the most internal water weight possible was directly pushing against any possible holes to the outside.

We also wanted to see how well they prevented outside debris and liquids from getting inside. We did this by submerging a container in a full bathtub for 10 minutes while looking for any bubbles. We also added a dark brown gardening chemical to the bathtub water so we could see any coloring or foul taste in the potable water.

We then cleaned the outside and checked the internal water for any signs of coloring against a control sample.

Crush tests

Some of the commonly bought containers on Amazon are surprisingly flimsy. Even some of the ones we purchased for our field test (after weeding out the obviously bad ones during research) already had dents and dings in their plastic walls from shipping.

We did two different crush tests. The first was realistic, where we assumed you might stack two full containers of water on top of each other. For example, a jerry can can be laid flat on its broad side with another full jerry can layered on top. They’re usually not designed to do this, but it could feasibly happen. Whatever can was put on top had five gallons of water, or ~40 pounds.

We then did a more extreme crush test where an adult woman weighing 150 pounds stood on top of the strongest and weakest part of a container. We looked for any leaks, cracks, or signs of warping and distress in the plastic.

Drop tests

Carrying heavy water jugs around can be tough, even if they have a handle. So we dropped full containers from multiple heights onto concrete.

The first test was a simple “tip over” test. We tried to knock the container over from a normal standing position onto a hard floor.

The second test was a realistic “drop it while carrying” test. For each container, we carried it the way you normally would. For most containers that means carrying it in one hand down by the side of a thigh. While walking normally, we lost our grip and dropped the container onto concrete. We did this three times per container.

For a more extreme drop test, we pushed the container from a standard kitchen countertop height of three feet. We did this three times per container.

Our choice: Reliance Rhino 5.5 Gallon Container

Top Pick

Best container for most people:

Reliance Rhino 5.5 Gal Water Container

Toughest container in the middle tier price class. Somewhat stackable for short term storage. Comes with everything you need. Survived our drop and crush tests.

Our pick for the best emergency water container for most people is the Reliance Rhino 5.5 gallon can.

We found some price inconsistency with this product, with list prices ranging from $20 to $35 and an average around $25. That makes it a few dollars more expensive than its Reliance siblings or the Scepter budget can. This difference makes sense given it’s built to be the toughest of the group with more, stronger plastic in the construction. If you are only able to find it for more than $30, we’d suggest waiting or buying the upgrade USGI Military Can or the Scepter 5 Gallon.

The Rhino is well named — it’s easily the most durable container we tested under $30. It was the third most durable of any portable container we tested, losing to only the more expensive USGI military cans and WaterBricks.

In our crush tests, the Rhino had no noticeable warping, cracks, or plastic distress. Although at one point we accidentally placed 150 pounds solely onto a two inch weak spot in the side wall, and it did create a dip that stayed in the plastic for about an hour afterwards.

The Rhino handled all of our drop tests very well. In fact, because of its skinny and tall stature that carries well against your thigh, it landed upright every single time we dropped it while walking.

It’s the only tall and narrow jerry-can-style container that is designed to be (sorta) stackable. One of the large side walls has a female pattern while the opposite wall has a male pattern. The solid and strong strut that runs diagonally across the wall will hold multiple containers together if they are stacked vertically (with each can laying on its side) or if the cans are standing upright but pushed closely against each other.

Although not marketed as a stackable container and not as stackable in practice as our space saver pick, we were impressed by how well the Rhino stacked. However, we were disappointed that the side walls with the stacking features arrived a little bowed out, which made for a less than ideal fit when stacked.

The Rhinos were not designed to be stored this way, and we wouldn’t recommend it. But if you needed to put them in a car or something similar for a short duration, this design gives you a few great positioning options that no other sub-$30 container could.

We did find that when laying on its side and stacked, with all the cans full of water, there was enough internal pressure against the seals where it caused a small drip leak out of both the main cap and airflow vent. It was about a drop every 1-2 minutes. All cans of this style showed this kind of drip leak when under a heavy load. Since you wouldn’t store them this way for the long term and the drip was mild, we thought it was OK considering the price and other factors.

It uses the common reversible water cap and spout, and everything was included in the purchase. The short spout rests inside the can while closed, which you then remove, flip around, and tighten down with the neck ring. This is not our favorite method because each time you touch the spout and then put it back inside the water, you increase your chance of contamination. But only the more expensive USGI and WaterBrick options avoided this problem, and the Rhino spout was much more sanitary than the Scepter 5 Gallon spout.

We also found it a little difficult to twist the caps down hard enough to prevent any leaks when laid on its side or suspended upside down, but it was doable.

Because of its relatively smaller 5.5 gallon capacity and tall, narrow frame with topside carrying handle, the majority of our reviewers found the Rhino to be the easiest to carry out of all the containers tested (except for the lightweight 3.5 gallon WaterBrick). It fits naturally against your thigh while carrying, compared to bulkier containers like the 7 gallon Aqua-Tainer cube.

Our main criticism of the Rhino is the airflow vent. It uses a twist style cap, which is greatly preferred over the push pin style plugs, but it had an unusually cheap and frustrating plastic connection piece that keeps the cap from being lost.

While great in theory, this cheap connection piece was poorly designed and frequently gets twisted up against the main body when you open the air valve. We didn’t worry too much, because even if this retainer piece broke (or you intentionally broke it), the threaded cap isn’t likely to be lost.

Upgrade: Scepter USGI 5 Gallon Military Water Can

Upgrade

Best overall can:

Scepter 5 Gal Military Water Can

The best overall water can we've ever tested. Built tough. Military tested features. Very large fill hole, secondary spout hole, screw top airflow vent. Nice spigot accessories.

Great add-on:

USGI Military Water Can Extra Spigot Hose

Excellent accessory for the USGI military cans. Buy one and keep it in a bag nearby. Attaches to the normal spout, gives a nice spigot pour through flexible hose.

These US Government Issue military-spec water containers are actively used by the US and Canadian militaries. You can tell this container was designed based on years of practical military field use. It carries well, has molded feet for stability, and is more stout than the tall and skinny Reliance cans.

Two companies manufacture this container: Scepter and LCI. Scepter is made in Canada and is considered the higher quality / original maker of this can. The LCI cans are often sold under their in-house Skilcraft brand, which are made in America via a program that employs disabled and blind people. Although the differences seem small, we believe the Scepter cans are higher quality and worth the roughly $5-10 extra compared to LCI. However, if you’re looking for the cheapest military style can possible, you can buy directly from LCI (plus $10 shipping).

The Military Water Can is extremely tough and should easily last you 10-20 years. Mil-spec standards require a minimum wall thickness of 0.1 inches or 2.5 mm, and you can feel it when handling this can. You don’t want to drop it off a two story building, and the caps are a relatively weaker plastic, but we would trust it in the field over any other jerry can style option.

The main 4” hole is massive, which is great for filling and rapid draining (like if you needed to quickly put out a fire). The cap is easy to put on and tighten down by hand, although you can buy a bung wrench for that extra torque. There is a built in ‘child lock’ feature on the main cap, with a plastic tab that has to be manually lifted over a bump in order to unscrew the cap. It was easy to miss the first time you pick it up, but even the 10 year old child we tested it with figured it out in about a minute.

Unlike the cheaper jerry cans, there are two separate caps: the main one covering the large fill hole, and a second, smaller 1” twist cap on top of the main cap that you can open just for pouring. There is no extra spout that you have to reverse and add. We like that because it means there are no parts you touch with your hand or expose to the outside that then sit inside the water.

The .5” airflow vent is also a small twist cap built into the larger main cap. Unfortunately, the first unit we received had a small leak in the airflow cap. We could tell it was a manufacturing issue from when the plastic was injection molded. But after a quick return and replacement, things were fine.

This wasn’t a major issue for us because every single water container on the market has reports of leaks and cracks, so it’s simply a game of chance. Always check your containers after buying.

We bought an extra $28 accessory that screws onto this smaller drain spout. It’s a flexible tube about one foot long with a nice spigot at the end. Although the can works fine without it, we loved this accessory and highly recommend it. Just keep it in a dry ziploc bag in the same place you store the container.

The USGI can passed all of our crush, drop, and submerge tests with no issues. Although, whenever we dropped this canister in our “dropping it while walking” test, it never landed upright. This is because the carry handle is off center, so it carries a little tilted front-to-back.

Our largest complaint is that the indexing on the main screw cap can be frustrating. So when you tighten it down by hand, the spout doesn’t line up exactly where you’d expect it to. We didn’t find it made a difference in pouring, but it seems like a silly oversight by the manufacturer.

Budget: Reliance Aqua-Tainer 7 Gallon Container

Budget

Cheapest way to store enough water:

Reliance Aqua-Tainer 7 Gal

Good value in a cheaper package. Stores more water than normal for its price class, but may be too heavy for some. Comes with everything you need. Not as durable and may crack, but does have five year warranty.

The Reliance 7 gallon Aqua-Tainers are very popular because they’re cheap and found in lots of stores like Walmart. Although you clearly get what you pay for, Reliance did a good job building an affordable option that is surprisingly nice for its price class.

The plastic and construction quality is better at $20 than some of the options we tested at $30. But we definitely noticed some warping and inconsistencies in the walls. Particularly when full, you can see a kind of bloated bladder effect that pushes out against the sides.

The Aqua-Tainer looks very different than other options. It’s basically a stout cube with a handle and spigot on top that you can tip on its side so the spout is at the relative bottom of the tank, hanging over something like a table top. That makes it a stable option you can leave as-is and use over a few days with a simple turn of the spigot.

The design lends itself to getting banged up more easily than other types of containers. We created some big dents in the corners during normal day to day use simply from walking around corners, etc.

There are a lot of reports in Amazon reviews of leaks and cracks. On the one hand, we find this to be the case with almost any container (even our durable upgrade pick had a small leak in the first unit we bought). But the cheaper Acqua-Tainer is much more likely to need to be replaced in the future compared to the Rhino.

The seven gallon capacity might seem like a bonus over the other 5-6 gallon options, but in practice, most of our reviewers noted that they wished it was a smaller six gallons. That extra 8-10 pounds of weight and extra storage space needed for the extra gallon made a meaningful difference in terms of ease of carrying and use. It also contributes to the larger side walls that can bend or break.

It comes with a reversible spigot. When stored, the spigot is screwed to the inside of the cap, sitting in the water. You remove the cap, unscrew the spigot, flip it to the other side, and rescrew. We like that Reliance made a screw cap style cover for the airflow vent.

For the price, we thought the caps and pieces were well built and we saw no leaks around the connection points. However, where were reports on Amazon of the white plastic spigot and cap cracking over time.

You put your hands all over the spigot while twisting it on or off, which then sits back into the water when stored. Another possible contamination issue is that when the spigot is stored inside the cap, the internal tube of the spigot is exposed to the outside world. Dirt and bacteria could get inside the tube, which would then flow out of the spigot when you use it.

Not a huge deal, especially considering that the best role for this container is for non-critical water use in situations where it won’t be moving around much — for example, you open it up once, lay it on a table, then keep the spigot on the outside as you use the water in your home over a few days.

Best space saver: WaterBrick stackable containers

Stackable

If you are space constrained:

WaterBrick 3.5 Gal

Ultra-stackable up to five levels high. Mediocre caps and spigots, but the best way to store water in tight spaces. Very durable, you can even use them as tables or defensive walls. Expensive.

If space efficiency is your top concern, consider the WaterBrick. They aren’t cheap — we paid around $65 for a set of two with one water spigot. You can get sets of 4 or 8 with one spigot for $110 and $185, respectively. Each set of four bricks is 14 total gallons, a two week supply for one person.

WaterBricks are specifically designed to be stacked. They are small at 3.5 gallons each and start off as a “do it all” container — the company advertises storing things like dog food and beans in addition to water.

For more information, please visit fbe lined.

The default cap used on each container is a simple flat cap without any water specific features. The mouth is nice and wide, but it isn’t practical to use for water unless you buy the extra water spigot cap. Sometimes a store will bundle the sets of 2, 4, or 8 bricks with one water spigot cap, but not one for each container.

As a result, you end up playing musical chairs with some of the pieces. If you have a stack of four WaterBricks filled with water and you want to use one, you have to attach the carry handle, remove the container from the stack, stand it on its vertical end, remove the carry handle, remove the storage cap, and install the water cap.

You cannot use the carry handle and the water spigot at the same time. The handles are nice and hold the container in an easy vertical position when carrying. But because they’re designed to be removable, they will pop off when you don’t want them to, which caused a number of frustrating moments during testing.

The spigot itself is mediocre. The container does not have a separate airflow vent to help with pouring, so the spigot is designed to let out water and let in air at the same time. This creates an odd chugging noise and water flow.

The spigot sits halfway up the container when in use. This means that once the water level is below 50% you have to tilt the brick with one hand while operating the spigot or holding a cup with the other. There are no built in handles or practical places to hold on to, so this can get a little awkward.

When looking at the water cap and spigot, we were concerned about some of the seals. Particularly the seal between the plastic cap and the spigot housing that seats through the middle of the cap. The assembly of pairing the cap and spigot together is not nearly as nice as similar options on the much cheaper $20 Reliance Aqua-Tainer.

We didn’t see any unreasonable leaking when we tested storing the water brick on its flat side, full of water, with the water cap on and spigot closed. However, storing it this way long term could still cause issues. Because the cap is on a vertical side wall, it’s the only container under seven gallons that we tested that had the weight of the internal water pressing against the seals during normal storage.

It’s reasonable to think the soft rubber gaskets used would degrade over time from constant water pressure and contact. There are Amazon reviews that mention this issue.

These all feel like silly design oversights by the company. If they made a better quality water cap and spigot, these problems could be avoided.

The container itself is very sturdy — probably the most solid-feeling container under seven gallons we have tested. At 3.5 gallons a piece, that means the walls have less surface area, which means less warping. Because they are designed to be stackable, the plastic is very thick and there are specially designed support struts throughout the container. We put 150 pounds on top of the container and it had no noticeable effect.

The WaterBrick shines when used as designed: to stack multiple containers in the most space efficient way. It is inch-for-inch the best way to squeeze 15 gallons of water into the smallest space possible.

They stack better than any other stackable options we’ve seen. When stacked, they are very sturdy and we’d feel comfortable stacking them three or four levels high. You can interlock them in alternating directions for added stability, and you can even use them for building makeshift structures or a defensive wall that slows down bullets.

It’s unfortunate the WaterBrick fell short on the more important qualities like ease of use and spigot quality, because if it was just a little bit better it might have been our top choice.

If you’re living in a home with very little spare space, it might be worth the extra money to get the WaterBricks. You can fit each one into smaller spaces than any other container or stack them together to store your 15 gallons per person in the most space efficient way possible. Just be sure to buy some extra water caps and keep them in a sealed ziploc bag nearby.

Competition

Scepter 5 Gallon Water Container. $25. We actually really liked this container — it almost won the overall pick and budget category. There were just a few flaws that kept it from being our top choice. But if you can’t find the Aqua-Tainer or you’re particularly worried about its size and durability, this container is a great backup budget choice.

Scepter has a good reputation for quality water cans. They are one of a few manufacturers that make our recommended upgrade pick, the USGI military style jerry cans. This five gallon can is their more affordable option. At around $25, it’s meant to compete with the Reliance products.

Although it’s a jerry can, it has a wider base and tapers off towards the top, which gives it a nice little boost of stability compared to straight and narrow cans like the Reliance Rhino. It was the sturdiest option we found in the $20 class. The airflow valve cover was very nice. The main spout cover had serrated teeth that helped with tightening down or opening the cap with your bare hands.

The pour was the nicest out of any container we tested, in any price range, except for the extra add-on accessory spigot for the USGI can. The great pour is due to a unique dual pipe design in the unusually long spout. But the spout was also flimsy, and even in our testing the edges of the plastic started to fray.

The spout is also flexible, with accordion folds in the middle. While nice for flexibility, we dislike it for long term storage because all of those nooks and corners are hard to clean and can harbor bacteria. We also prefer a shorter spout, because with these reversible designs, every time you remove, use, and return the spout, you run the risk of touching it with your hands or other contaminants, which then get dipped back into the water.

When filling the container, the neck hole was the narrowest out of any we tested, which was a slight annoyance.

Saratoga Farms Stackables. $100 for the four-pack of 5 gallon cans. We were really disappointed in the Saratoga Farms 5 gallon stackables. The plastic is cheap and was already warped and dented just from shipping. We get the impression the product designers had long term storage in mind, but it didn’t come together well at all. For example, the airflow vent arrived without a hole in the vent — you had to puncture the hole yourself. This theoretically helps cut down on contamination and leak risk, but could be impractical in an emergency.

The caps are poorly designed, with a saw-tooth ratchet that locks in once you tighten the cap for the first time. But once you open the cap, it breaks away the ratchet ring and can’t be used again (like a new soda bottle cap). Their core feature, the ability to be stacked, was almost laughable — we would never feel comfortable stacking them even two levels high. The interlocking design was not nearly robust enough, and it only prevented the container from shifting along one axis. If you pushed along the other direction, it would slip right off!

Reliance Desert Patrol 6 Gallon. $30. The Desert Patrol is a popular water container and one we’ve personally and successfully used for camping and offroading. But we disqualified it for survival needs almost immediately. It has a standard single-handle jerry can design with reversible water cap and spout design. But when compared to its brother the Rhino, the plastic feels thin, it warped easily, and it doesn’t stack well. It totally failed our drop tests, with the back wall crumbling in on itself.  It uses the traditional push-pin style plug for the airflow hole, which is basically an automatic disqualifier because it’s too flimsy and can easily leak water or let contamination inside.

Reliance Water-Pak 5 Gallon. $27. We chose not to include the Water-Pak in our field testing because of reports about a cheap and difficult carrying handle, which you can clearly tell from the pictures is less robust than its siblings. But with how disappointing some of the other products in our field test were, and the unique tall cube form factor, we might choose to test the Water-Pak in the future.

Reliance Aqua-Pak 5 Gallon. $25. Although an interesting cheap option from Reliance that seems more durable than the Aqua-Tainer and is marketed as stackable, it was automatically disqualified because of the push-pin style airflow plug and reports of cracking when stacked. We might test the Aqua-Pak in the future.

Reliance Jumbo-Tainer 7 Gallon. $37. The Jumbo-Tainer is a better container than its brother, the Desert Patrol. But it was quickly disqualified because of the push-pin plug for the airflow vent. We like the dual handles and reversible spigot (similar to its other brother, the Aqua-Tainer). It’s more rigid than the Desert Patrol, but not as stackable as the Rhino.

Igloo Cargo II / Rubbermaid 6 Gallon Water Containers. $20. We wouldn’t have chosen to include the Igloo in our field tests, but we had access to one anyway. Igloo has not done a good job defining their product offerings and there are a lot of confusing SKUs listed on Amazon and Walmart for these lines. Note that it appears the old Rubbermaid designs were absorbed into the Igloo line. We tested the Rubbermaid six gallon container in person and thought it had some nice features, like a sturdy design, dual handles, and molded stability feet. But the new Igloo’s have a push-pin style airflow plug, which is a disqualifier.

Ace Roto-Mold 10 Gallon Water Storage Tank. $150 after shipping. We were skeptical ahead of time about a 10 gallon tank, but wanted to include it for proper testing against the more popular short term options. It’s tall and cylindrical with a giant twist cap on top and an industrial ball valve on the bottom. This container, and other ones like it, would be solid contenders if they were smaller or somehow more mobile. Wherever you fill it with water is where it’s going to stay, unless you use multiple people or a wheeled cart. The lack of mobility means that spigot at the bottom will be difficult to use unless the tank is elevated. The top cap is too large for residential use, which increases chance of contamination, and the overall price was too expensive at $150. So it was disqualified for this recommendation.

Midwest Can Company 6 Gal. $15. Disqualified during research. Inconsistent messaging from the manufacturer about the plastics used. Knowledgeable Amazon reviews say the can is marked as flammable plastic #7 and likely contains BPA.

Wedco Briggs & Stratton 5 Gallon Water Can. $25. Disqualified during research. Poor quality spout and a push cap style airflow vent cover. A wide base makes this can stable and the dual handles are nice, but results in being very space inefficient compared to similar products.

Hudson Exchange 5 Gallon Plastic Hedpack. $17. Disqualified during research. Too many reports of durability problems. The plastic is good grade but too transparent and likely intended for shorter term storage, like restaurant or transportation use.

Tolco Heavy-Duty HDPE 5 Gallon Plastic Dispenser Carboy. $42. Disqualified during research. Too transparent, too many reports of leaks, and too expensive for what you get.

Coleman 5 Gallon Water Carrier. $21. Disqualified during research because we couldn’t find consistent inventory stock in major stores like Amazon and Walmart.

AquaPodKit 65 Gallon Bathtub Emergency Water Storage. $20. We like this kind of bag that fills up inside your bathtub in an emergency. But it’s a nice-to-have bonus and not an appropriate contender for your main two week water supply.

Poly Tanks | Water Tank FAQs

1. What is a plastic water tank?

A plastic water tank is a container made to store and deliver water for various uses and work settings that has been manufactured from the synthetic material known as plastic. The types of plastics used to make water tanks are polyethylene and polypropylene, with polyethylene being more popular. 

Plastic water tanks are engineered to safely and securely handle small to large volumes of water. Depending on the plastic water tank type, they are made to handle either potable or non-potable water. Plastic water tanks are manufactured in a range of styles and volume sizes to match up and meet the needs of different applications.

2. What is a water tank made from? What materials are used to make modern water tanks?

Most modern water tanks are made from either plastic or metal. Plastic water tanks are typically made from polyethylene, polypropylene or fiberglass reinforced plastic (abbreviated FRP, also often listed just as fiberglass for short). Polyethylene water tanks are by far the most common in use across applications today. In the manufacture of polyethylene water tanks, the materials used are the raw plastic known as resin, ultraviolet stabilizing compounds usually carbon black or titanium dioxide, and a color pigmentation compound if the tank is to be any color other than white.

Polyethylene plastic is manufactured in various density types, with the most common being low density (LDPE), medium density (MDPE) and high density (HDPE). These types can also be listed as linear polyethylene – low density linear polyethylene, medium density linear polyethylene, and high-density linear polyethylene. Note, these are used to indicate different types of the same base plastic material. Most plastic water tanks made from polyethylene are fabricated from high density polyethylene. 

Polyethylene can also be manufactured differently to produce cross-linked polyethylene (XLPE). XLPE is not commonly rated or approved for use in water storage, more specifically, potable water storage. XLPE plastic tanks are most used to store chemicals. Metal water tanks are made from either galvanized steel or stainless steel.

Metal water tanks offer a long lasting, highly durable water storage solution with a volume range capable of far exceeding plastic tanks. However, metal water tanks are often much more expensive versus plastic water tanks. Depending on the metal tank size and manufacturer, a metal water tank may still feature a food grade polyethylene plastic liner designed to hold the water within the metal shell.

3. How are plastic water tanks made?

How plastic water tanks are made depends on the raw plastic material used as well as the particular type of water tank. Plastic water tanks are made through specific production processes that use a mold that sets the shape, size, and design of the water tank to be made. The most common plastic water tank manufacturing processes are rotational molding and blow molding. 

Rotational molding, also known as rotomolding and rotocasting, is used to make most rigid-walled water tanks such as vertical tanks, underground cisterns, utility tanks, and rainwater tanks. Rotomolding uses powdered raw plastic resin, a product mold, heat and a rotating equipment apparatus. Plastic resin is placed in the mold, heated to the resin’s melting point, and rotated in a mechanical pattern designed to distribute the molten plastic material throughout the mold to create the desired product to a certified thickness per engineering standards. After molding, the product is cooled and then released from the mold, yielding a water tank that is both effective and certified for use in storing water.

Blow molding is used to make water tanks that have semi-flexible walls such as the 275 gallon tote and 330 gallon caged IBC totes. Blow mold plastic manufacturing uses an openable product mold, heat and a resin delivery apparatus that uses air. Resin is heated to molten temperatures and air is used to blow the heated plastic resin into the product mold to form the outer walls of the container and leave a hollow interior.

4. Is a plastic water tank safe?

Yes, plastic water tanks and the materials used to make them have been thoroughly researched, engineered, tested and certified for safety. They are safe for use and reuse in providing water, storing water long term, standing up against the elements, workplace conditions, and safe for long term placement, installation and use. 

The polyethylene plastic material used to make water tanks is rated as inert by U.S. national safety standards for use with water for the lifespan of the container. Being inert means polyethylene will not affect water quality, will not leach chemicals of any kind into the water when stored, nor be affected itself by any reactivity with the water. 

Certification and approvals can vary by product but often include the United States Environmental Protection Agency (EPA), the Food and Drug Administration (FDA), the Code of Federal Regulations (CFR), the National Sanitation Foundation (NSF), and the American National Standards Institute (ANSI).

5. Do plastic water tanks have BPA or phthalates?

No, poly water tanks do not contain BPA or phthalates. Bisphenol A (BPA) and phthalates have never been used in the production of plastic water tanks fabricated from polyethylene resins. The use of BPA was largely reserved for polycarbonate materials but has seen considerable phase-out in production due to BPA’s known health concerns. 

Phthalates are a chemical often intentionally added to plastics to increase their strength in flexibility. They are most used in plastic products made from polyvinyl chloride (PVC) and are uncommon in products made from polyethylene. This especially includes poly water tanks as U.S. health and safety standards restrict phthalates from potable water containers. See the CDC for more info on phthalates.

When shopping for modern water tanks made from polyethylene, rest assured and know the containers we offer are safe and approved to be free from BPA, phthalates or any other harmful materials of concern. Our water tanks are rated and certified to ANSI and NSF 61 standards for drinking water use.

6. What is the advantage or benefit of a polyethylene water tank versus other material types?

Compared to many other materials types, plastic poly water tanks are lighter in weight, lower in cost, easier to install, easier to transport and relocate, have improved weatherability, improved resistance to corrosion, will not rust, and resist damage from impacts and drops. 

When used exclusively for holding water and well cared for, polyethylene tanks offer a significant service life, and when combined with a low purchase price, provide an unbeatable cost-to-service life.

7. Is the water in a water tank safe for drinking?

Only plastic water tanks manufactured from FDA approved food grade, virgin polyethylene resin that have been ANSI, NSF 61 certified are considered safe and acceptable to drink from. Such water tanks are known as potable grade water tanks. Polyethylene plastic as a material and when certified to these standards, has been extensively tested for safety and used for direct food contact uses for many years across industries and applications.

There are some plastic water tanks that are not certified for potable water and considered non-potable grade water tanks. The reason they are considered non-potable is most often due to specific additives or colorant added to the tank during manufacture. Yellow water tanks are the most common non-potable plastic water tanks and are often used in agriculture.

8. What plastic water tank types are available?

Polyethylene plastic water storage tanks are available in the following types:

  • Vertical Aboveground 
  • Underground Cistern 
  • Rainwater 
  • Slimline, also known as Doorway
  • Emergency 
  • Conical 
  • Portable style water tanks which includes
    • Utility Tanks 
    • Loaf Tanks 
    • IBC Totes 
    • Leg Tanks
    • Pickup Truck Bed Tanks
    • ATV / UTV Tanks

Plastic water tanks are also made as on-board vehicle water tanks for recreational vehicles (RVs) and boats.

9. Do tank sizes vary by water tank type?

Yes, the available size range for water tanks will vary extensively by the type of water tank. Polyethylene water tanks are commonly manufactured in gallon capacities from 1 gallon up to 20,000 gallons. The full range of volume sizes is not available for each water tank mold style, so some tank types can hold more water than others. Each water tank style will have its own offerings in gallon sizes depending on its selective engineering. 

Below is an overview of general size ranges for the most common water tank types:

  • Vertical Above Ground: 10 Gallon to 20,000 Gallon
  • Underground / Cistern: 250 Gallon to 10,000 Gallon
  • Rainwater: 100 Gallon to 10,000 Gallon
  • Emergency: 100 Gallon to 500 Gallon
  • Doorway / Slimline: 100 Gallon to 1,000 Gallon
  • Leg: 30 Gallon to 6,025 Gallon
  • Utility: 7 Gallon to 1,000 Gallon
  • RV / Marine: 3 Gallon to 200 Gallon
  • IBC Tote: 110 Gallon to 550 Gallon

10. Which water tank is the best for use at home?

The water tank best suited for use at home will depend on the intended application for the water tank. Common water tanks used at home are vertical storage tanks, underground cisterns, rainwater tanks, slimline / doorway tanks, emergency water tanks, and portable water tanks. 

Vertical storage tanks are good for an overall range of uses, are best for large water volume needs and permanent to semi-permanent installations. Our selection of vertical water tanks can be found here.

Cisterns are best for long term underground water storage systems, the benefits of underground installation, and are often used in well water and rainwater applications. Our selection of underground cisterns tanks can be found here.

Rainwater tanks are best for rainwater harvesting systems and use as they come ready for easy setup and use. Our selection of rainwater collection tanks can be found here.

Slimline tanks are best for situations or properties with limited or restricted space that makes installing larger tanks difficult. Our selection of slimline doorway tanks can be found here.

Emergency water tanks are best for allowing installation and water storage indoors and providing reserve water in disaster preparedness and water shortage applications. Our selection of emergency water tanks can be found here.

Portable water tanks are best when water needs to be transported by a vehicle from location to location for different uses. Our selection of portable water tanks can be found here.

11. What colors are available for water tanks?

Polyethylene water tank colors include white, black, green, blue, brown, red, and yellow. Green, blue, brown and red are also often available in various shades such as mist green, dark green, brick red, light brown, etc. Metal water tanks made from steel and stainless steel are often the natural color of the steel. Some metal water tank suppliers offer their products in various colors or design options. Green water storage tanks as well as black water storage tanks are the more popular and commonly used tank colors.

12. Does water tank color indicate tank quality?

Yes and no, the color of a water tank can indicate tank quality, but it can also depend. When referring to polyethylene water tanks, there are only two quality grades to consider and that color can relate to: 1) potable for drinking water uses, also known as food grade, and; 2) non-potable for non-drinking water uses, also known as non-food grade. 

Most water tank manufacturers and distributors clearly list the tank grade for sale. Most often, potable grade water tank colors are white, black, green, blue, beige and sometimes red. The most common non-potable grade water tank color is yellow. Note, this may not always be the case as non-potable grade water tanks can sometimes be available in black, green and other colors as well.

13. Does water tank color affect algae growth?

Yes, the color of a water tank can affect the rate and extent of algae growth inside the water tank. However, this is actually more dependent on the opacity of the tank rather than its color, yet these two concepts do go hand-in-hand. Tank opacity relates to the amount of sunlight that makes it through the tank walls and reaches the stored water. The more sunlight passing through a poly tank’s walls, the more algae that will be able to grow. 

Tanks that are lighter in color are often less opaque, making them more translucent, meaning they let more sunlight through the tank walls. White colored water tanks are often the most translucent of all available water tank colors and therefore frequently experience the greatest amount of algae growth.

Water tanks that are darker in color are often more opaque, making them less translucent, reducing the amount of sunlight capable of passing through the tank walls, if not eliminating it altogether. Black and dark green water tanks are the most effective in reducing algae growth in long term water storage.

Many black and dark green water tanks can completely block incoming sunlight. If no sunlight makes it through, there will not be any algae growth in the water, even long term. 

14. How do I know if algae will grow in my water tank?

On a sunny day, slightly open the lid and peek into the poly tank. If the inside walls are illuminated, this means light is coming in and algae may eventually grow in the stored water. If you do not see light, then the tank has been manufactured in a way that blocks sunlight and algae should not grow in the tank.

15. What are common plastic water tank sizes and prices?

Plastic water tank sizes and prices depend on the type of water tank. For vertical water storage tanks, sizes between 250 gallons and 4,500 gallons are the most common with prices ranging between $400 to $4,000. The following table is an overview of common plastic water tank sizes and prices by type of tank. Note, prices are average approximations of potential cost expectations, but are an excellent starting point to get an idea on water tank pricing.

16. Can a plastic water tank be repaired?

Yes, a plastic water tank can be repaired depending on the extent of the damage and the type of repair needed. For large tears or cracks greater than 12 inches in length, it is recommended to replace the water tank instead of trying a repair.  Repair for such large damages will most likely be a temporary fix at best before the damage will return (and often if not worse than before). At this point, tank failure should be expected to eventually occur. 

17. How to repair a plastic water tank at home?

Repairing a leaking water tank at home is recommended to be performed by a licensed professional. However, it can be performed DIY if you have the right tools, materials and if the damage to be repaired is not too large. Cracks or tears in a water tank wall larger than 12 inches, especially when near the bottom, are often considered too large for a long-term repair and recommendations are to replace the water tank. 

If trying to DIY repair a cracked poly water tank, we have outlined the tools needed and the best recommended method below.

Proper Tools and Materials to Repair a Plastic Water Tank:

  • Poly Welding Gun
  • Plastic Repair Epoxy, also called Polyethylene Welding Rod or Welding Wire
  • Drill w/ 1/8 in. Drill Bit
  • Rotary Tool w/ Abrasive Rotary Attachment

Recommended Method to Repair a Plastic Water Tank

Prior to the repair, it is important to make sure the tank is clean and dry on both the inside and outside of the tank. Drain the tank completely or beneath the point of the damage. Clean the surface with soap, water, a rag and/or pressurized air. Use whatever extent necessary to provide a clean, dry working surface as water, dirt, oil, dust can all potentially affect the effectiveness of the plastic repair.

It is recommended to move the tank inside, if possible, and away from wind, rain, and colder temperatures. The poly welding gun and repair epoxy are heat-operated, heat-activated, and heat-sensitive.

When the damaged tank area is clean and dry, use the drill and 1/8 inch drill bit to add two solitary holes: one above the crack and one below. These holes help distribute the stress weight associated with the damage and help prevent the damage from spreading further. 

Use the rotary tool to sand out a V-shaped groove in the damaged area. For this step, use the abrasive attachment head to sand grooves 1/2 inch to 3/4 inch deep the length of the crack.

After cleaning, drilling, and sanding, the next step is to use the plastic repair epoxy and welding gun. Always follow the directions labeled on the epoxy as it can vary by product and gun type. Ensure the welding gun is plugged in, heated and ready for use; heating may take 10-15 minutes. It is recommended to heat the damaged area to above room temperature; a hair dryer can be used for this step.

If using welding rods, cut one end of the rod to a point and load into the preheated welding gun. When ready to weld, place the welding gun tip at one end of the v-shaped damage groove, apply light pressure, and slowly move the tool from one end to the other, feeding weld material as needed. 

After the first welding pass, heat the welding material added to the damage to a smooth glaze. This allows the material to properly bond. The heat from the welding tool or  a hair dryer can achieve this. For depper damages, a second weld may be needed. If the weld doesn’t seem to fill the damage groove or seems unsatisfactory, perform the welding process a second time. 

When welding is complete, allow the water tank repair to cool and dry as long as recommended per the product label before using your water tank again.

18. Can I paint a polyethylene water tank?

Yes, a polyethylene water tank can be painted. Applying paint to a water tank exterior will not affect water quality or tank integrity. Painting a polyethylene water tank requires tank preparation and the right type of paint. 

Painting polyethylene can be difficult to have the paint apply and adhere long term. Without proper preparation of the tank surface or the right paint, most paint will remain only for a short time if not begin to immediately crack, chip and/or peel on drying. This happens due to adhesion incompatibility between the paint and polyethylene surface as well as the regular expansion and shrinking experienced by poly water tanks. 

Polyethylene water tanks have a high rate of thermal contraction and expansion that causes the tank to shrink when cooled and expand when heated. Keeping paint on a surface that is regularly changing due to ambient temperature fluctuations can be difficult and may occasionally require touch-up paint or full repainting.

19. How to paint a polyethylene water tank?

To paint a polyethylene water tank, the surface of the tank needs to be prepared to have the best painting results. Proper preparation requires removing the tank’s glossy, wax type surface if present, as well as ensuring the surface is clean and dry. Some polyethylene water tanks may not feature a glossy surface or may have lost it already over time due to age and/or sun exposure.

There are three recommendations on how to prepare polyethylene for painting. 

  1. Use a hand sander over the surface area to fully remove the gloss / wax coating. (Alternative sanding methods can be used, such as sand blasting, just be careful not to sand too much). 
  2. Use a commercial grade, heavy duty paint thinner and rag to remove the tank’s glossy coating. Paint thinner is also an effective method to completely dry and clean the water tank surface of any oils.
  3. Use fire to remove the polyethylene’s outer coating by gently passing it over the plastic’s surface. A propane gas torch or open flame gun are recommended fire sources for this method. This method requires the greatest attention to detail and safety to ensure heat damage does not occur. 

There are three recommended paint types for use on polyethylene.

  • Elastomeric Paint 
  • Exterior-Rated Latex House Paint 
  • Automotive Grade Urethane Based Paint

Elastomeric and latex paint options are the top recommendations for painting polyethylene due to the improved flexibility characteristics of these paint types.

Note, even with the preparation and recommended paint types, it is still possible the paint will not remain indefinitely and may eventually experience peeling and need reapplication.

20. Do plastic water tanks vary in how thick they are?

Typically, yes. This question can refer to two distinct concepts concerning sidewall thickness common to plastic water tanks. A plastic water tank varying in thickness can refer to either the uniformity / consistency of material thickness in an individual tank or between different tanks, as from different manufacturers. In both circumstances, a water tank can, and often will, vary in how thick it is. 

Concerning wall uniformity in an individual tank, it is an intentional practice of the polyethylene water tank manufacturing process to rotationally weld different parts and locations to different thicknesses. This is by engineering design to ensure the tank meets the criteria established per codes and regulations to withstand the pressures, weights and performance stressors associated with its use. On a well-manufactured poly water tank, the top, bottom and sidewalls will all differ in their respective thicknesses. Sidewalls will be of varying thickness from top to bottom, the tank’s bottom will be the thinnest across the tank and the top will be similar to the side walls.

Different manufacturers can produce same volume sized water tanks to each other but differ in how thick they are. The reason for the difference is often in the raw material polyethylene resin choice, its quality, as well as the steps and design used in the rotational molding process for the water tank. A lower quality resin will require more resin than a tank produced with higher quality resin to yield the same design, safety and engineering performance standards. The result will be thicker walls and a heavier tank.

21. Why do water tanks with the same volume have different weights?

The reason water tanks with the same volume can have different weights is often due to how thick the tank is, that is, how much material is used to manufacture the tank. Water tanks that are heavier than another with the same volume for the same water tank type often have been made with more raw material than the lighter tank. The reason for this is often because a raw material that is poorer in quality is used to make the tank. 

Another reason for the weight difference can be from engineering design differences between the same volume tanks. However, if the tanks are fairly identical in design, but have a significant weight difference, it is most likely due to how thick the tank is due to the quality of the polyethylene resin used to make the tank.

22. Does the thickness of a water tank matter?

Yes, but not for the reasons usually thought. The thickness of a water tank matters most in terms of manufacturing quality between different companies and the select resin options used in the production of their polyethylene water tanks. Just because a company provides a water tank that has thicker walls does not necessary mean that the tank is of better quality. Many times this can actually mean the opposite as an increased amount of lower quality resin may have to be used to produce a water tank that meets the engineering design criteria required per regulatory oversight and standards for the specific water gallon size in order to hold water safely. A thicker tank can often be noticed from a difference in the total tank weight between water tanks of the same volume capacity. 

23. Can two or more water tanks be joined together?

Yes, two or more water tanks can be joined together in sequence in a step-by-step style installation through the use of plumbing. Tanks can be joined from the top or from the bottom. Joining two or more water tanks together is a common practice to increase the amount of total water storage per location as well as for certain water handling and distribution systems. 

Joining water tanks together is also often done to add onto and expand an already existing water tank system. To join two or more water tanks together, you will need the additional fitting or fittings, the tanks to be joined and the piping to connect them.

Most water tanks have what are called “fitting flats” included in the design of the finished molded water tank product. These “fitting flats” are flat and level locations made for installing additional fittings, such as bulkheads, and allow more plumbing connections to be made to the tank. They are in addition to the one, (often two), fitting connection ports that come standard on most water tanks. “Fitting flats” are often located toward the top of the tank but are sometimes located along the tank sidewalls. In both cases, they are usually at a distance 90° to each other, sometimes 45°, sometimes 180° on vertical poly tanks. Technical drawing sheets for individual water tanks can be helpful in locating fitting flat locations if they are not apparent in the tank’s design.

24. What is the benefit of joining water tanks together at the top of the tank versus at the bottom?

Joining two or more water tanks together at the top will cause the tanks to fill up in sequence one-by-one after the other. In this method, tanks are often connected at a pre-set top inlet or a self-installed bulkhead. The first tank to receive water inflow will have to fill completely to the point of the plumbing connection before any water flows to fill the next tank and so on. 

Due to gravity and air pressure, the maximum water level for all tanks in a top-connected system will be limited to the height of the tank-union outlet on the first tank. Due to this, best practice is to place the first tank at the highest land level location to maximize the water volume in the succeeding tanks.

When tapping water from this connection setup, water will only be drawn from the individual tank being tapped. This means water will deplete from one tank and remain the same in the others. A method to withdraw from all tanks collectively and keep water levels uniform is to connect all tanks together at their outlet taps and link this to a solitary outlet valve. 

25. What is the benefit of joining water tanks together at the bottom of the tank versus at the top?

Joining two or more water tanks at the bottom will cause all connected tanks to fill up more or less evenly at the same time. To connect water tanks at the bottom means to use additional plumbing to join the tanks at their drain outlets. A system of tanks connected this way will only need one tap, usually at the lowest tank in the system. The lowest tank is the last tank in the plumbing sequence from the initial tank set to receive water. Due to laws in physics, when water is drawn from one tank, the water in all connected tanks will balance out until the entire system has an equal volume again. 

26. Can a pump be used with a water tank?

Yes, a water pump can be used to either fill the tank with water or draw water from a water tank. Adding a pump to a water tank system is common practice in distributing water so that it has adequate pressure for uses around a home, business, or farm. Without a pump, water from a water tank may not have enough pressure for use by equipment, plumbing, in appliances, taps, or any other possible fixtures such as showers and toilets.

When adding a water pump, it is important to the safety and integrity of the water tank that the air / liquid cubic volume displacement rate of the pump does not exceed the venting capability of the water tank. If this isn’t checked and verified, or if it is overlooked, it can cause over-pressurization or a vacuum-type scenario within the water tank which can have damaging results to the tank, its fittings or connected plumbing.

For distribution applications with a water pump, also ensure the rate of water drawn from the tank will not exceed the tank’s vent capacity to replace the water volume pulled from the tank. These scenarios are more common in bulk filling or bulk distribution applications.

27. Can a poly water tank be pressurized?

No, a polyethylene water tank is not engineered for pressurized applications, to function as a pressure vessel, or use in conditions that will create a vacuum inside the water container. Such scenarios can cause hazardous conditions for the water tank or plumbing system capable of collapsing the tank and/or causing damage to equipment or personnel. Normal pressure strains that arise from the use of a water pump are acceptable.

28. Is it important for a water tank to be vented?

Yes, venting is important for water tanks to release any air pressure that can build up inside the tank when the tank is being filled. Pressure buildup within a tank can also be due to heating. To fix this, many polyethylene water tanks feature an automatic venting lid designed to self-regulate excessive pressure buildup inside the storage container.

29. Why is the water pressure low in my water tank when I use the tap?

A common reason for low water pressure or a change in water pressure is a leak, crack or damage somewhere in the storage tank or in the connected plumbing system. Water tanks are made to maintain a set pressure inside the container due to the force of atmospheric pressure and the tank’s self-venting lid. A crack in the water tank will affect the ability of the relatively sealed, closed system to maintain a stable pressure because it creates an additional opening for air and pressure changes. 

It is possible for a crack to form on the top of the tank or above water level – where water may not leak and the damage could potentially go unnoticed. If you notice water pressure has changed from normal and unexpectedly from your water tank tap, check your tank and any attached plumbing for any leaks or cracks. Unnoticed damage could be the cause for the change in water pressure.

Low water pressure from a water tank can also be the result of insufficient gravity pressure driving water flow to taps connected downstream as well as too many taps connected to the water tank. A potential fix is to relocate the water tank to a location with higher atmospheric elevation, such as on a hill. Another fix for low pressure is to install a water pump or booster pump within the plumbing system between the tank and tap.

30. Where can I buy a plastic water tank?

Plastic water tanks can be purchased mostly online, at certain farm and hardware supply stores, and sometimes secondhand.

  • Water tanks for sale online are available from many e-commerce retailers who make shipping arrangements with freight handlers to deliver the water tank.
  • Searching farm and hardware supply stores for water tanks can be a hit or miss and often depends on your personal location and local demand for the product.
  • Finding a water tank secondhand from an individual, a farm or business can be difficult if no one is selling one. Also, the quality of a secondhand water tank can also be in question depending on how long it’s been used, how exactly it was used, and how well it was cared for.

Buying a water tank online provides the benefits of a wider selection of options to choose from in terms of water tank styles and volume capacities, delivery, and guarantee that you are buying a brand new, quality water tank.

31. Does a water tank need to be cleaned before first use? 

Prior to first use, it is recommended to flush rinse a water tank to clean out any potential residual dust or material from manufacturing.

32. When should a water tank be cleaned?

Water tanks are recommended to be cleaned annually or more frequently depending on the quality of the water stored, the location and color of the tank (for algae), and the application the tank is being used for. Algae, biofilms, and build-ups from hard water (water with minerals or sediments) are the largest reasons why a water tank will need to be cleaned.

Water tanks can be recommended for cleaning every 6 months, once a year, or once every two years – it largely depends on the particular use case and conditions. Some applications can require a cleaning frequency more often than every 6 months, while other water tanks may be okay to go with rarely being cleaned.

Water quality is a large factor in the cleaning frequency for water tanks. A tank that holds water with an increased amount of sediment or trace minerals (such as unfiltered groundwater) may need to be cleaned more frequently than a rainwater tank with clean, soft water that results from an effective system. The first example may need more frequent cleaning due to the potential for sediment buildup in the tank that can affect water quality over time, in plumbing that can cause a clog or perhaps the trace minerals promote growth of algae or bacteria. 

Water tank location and color can also affect how often a water tank needs cleaned. Water tanks installed indoors or away from direct sunlight will not experience as much algae growth. Dark colored water tanks can limit the amount of sunlight that makes it through or completely block sunlight. This will reduce or eliminate algae growth and therefore reduce the amount of cleaning that will be needed.

33. How do I clean a water tank?

There are multiple ways to clean a water tank. Some companies make products designed to help clean water tanks. However, a water tank can be cleaned without these.

To clean a water tank: (1) drain, (2) clean, (3) rinse, and (4) disinfect the new water, if needed. 

  1. Drain the existing water from the tank. Consider not being wasteful with the water drained in this step. Unless the water is increasingly dirty and believed unfit for any use, consider using it to water grass or gardens with non-edible plants. The water is also recommended to be drained into a storm water runoff system.
  2. Clean using soapy water and a non-metallic bristle brush to scrub the interior of the storage tank. Preferably, use an extendable brush with an adjustable head to help reach tank corners and avoid having to enter larger volume tanks. A DIY brush attached to a pole can suffice. Power washers are considered excellent tools for cleaning water tanks. Household bleach or baking soda are okay to use in cleaning and can help in removing algae, biofilm or sediment buildup within the tank.
  3. Rinse the water tank of the soap and water used in cleaning. Ensure a thorough rinse and drain and repeat as needed.
  4. Disinfect new water added to the tank, if necessary, based on the application and/or water source. 

For more on cleaning water tanks, see our Poly Tanks Series post How to Clean a Water Storage Tank.

34. Is it necessary to disinfect and/or treat the water in a water tank before it is stored?

No. It is not necessary to disinfect and/or treat the water in a water tank prior to long term storage. Treatment can be performed shortly before the time when the water is to be used. However, not treating the water before storage can increase the dirtiness of the tank and water over its storage timeframe, which can lead to more work in water treatment as well as cleaning the tank. Often, this is due to algae build up or microbiological growth. Treating and/or disinfecting a water tank supply prior to storing can help keep the tank cleaner and ensure your water is safe for use when it is needed.

35. What are the benefits of a rainwater harvesting water tank?

Rainwater harvesting is the practice of capturing, storing and using rainfall. Using a rainwater harvesting water tank can reduce your water bill, provide a sense of self-sufficiency, help with local water shortages, and help the environment with water conservation efforts. A rainwater harvesting water tank can even be used to provide all the water needed on a property, such as in off-grid living, when the right equipment and setup is used. For more on the practice of rainwater harvesting, see our Rain Tanks Series posts.

36. How do I know what size rain water tank I need?

Consider annual local rainfall amounts, roof size or other rain catchment area, and estimate regular water usage needs. These variables will help determine what rain tank size is needed or that may be best for your particular use case.

Annual rainfall amounts vary by geographic location and seasonally. The U.S. Government monitors, records and provides access to regular rainfall amounts. This data can be used to estimate how much rainwater you can potentially expect for your location. The EPA National Stormwater Calculator is an excellent resource for various information including local annual precipitation.

The following equation can be used to estimate your water tank size based on how much rainwater a harvesting system can potentially collect.

Rainwater Harvest Volume (Gallons) = Rainfall Amount (Inches) x Catchment Area (Square Feet) x 0.623

This equation can be used for any rainfall amount; example: a single day’s rain event, how much rain in a month, or a year’s worth of rainfall.

For more on this, see our post How Much Rainwater Can I Collect with Rainwater Harvesting.

37. How much rain is needed to fill a water tank?

To answer this question, know the gallon size of your water tank and the square footage of the rainfall catchment area – usually, this is the roof of a home, shed, barn or business. It doesn’t matter how steep or flat or how intricate a design the roof is when it comes to the square foot area of the roof and how much rain it will be able to collect. Often, the square footage of a roof is just slightly larger than the square footage of the home, which makes for a good estimate.

When you know the square footage of your rain catching area, calculating how much rain is needed to fill a water tank is easy:

Inches of Rain Needed to Fill Water Tank = Rainwater Tank Gallon Size ÷ [Square Feet of Roof Area x 0.623]

Note, for the above equation, the brackets indicate the roof area must be multiplied by 0.623 before dividing into the rain tank size.

38. Is it okay to use a rain water tank for drinking?

Rainwater is only considered safe and okay for drinking if the rainwater is properly treated to potable grade quality water to ensure health and safety. The United States Centers for Disease Control and Prevention(CDC) also supports rainwater harvesting use for drinking if treated. For more on this, see our post Why Should I Not Drink Rainwater (Before Treating It).

39. How do I make harvested rainwater safe for drinking?

To make rainwater safe for drinking, screen out all incoming debris, use a water pump, multistage cartridge filtration with a sediment filter, 5 micron filter and carbon filter, and a UV light water treatment system or treat the water with a chemical. For more on this, see our post How to Turn Rainwater into Drinking Water.

40. Where can I install a vertical water tank? What types of surfaces are okay? Do I need a foundation for my water tank?

Water tanks can be installed just about anywhere they can fit and should be installed on a flat, level, solid surface that provides full support to the bottom of the tank and is made from materials that will withstand the full weight of the tank when full of water. 

The best type of surface or foundation can depend on the water tank volume and therefore the tank’s total weight. Recommended surface types for vertical water tanks include a concrete pad, a base made of crusher dust, pea gravel, or directly on the ground. Pads or elevated stands made from metal or wood are also okay and often used given they are built in such a way to hold the weight.

A water tank foundation base is important for long term, secure installation, especially for large volume water tanks. A proper foundation will ensure tank stability and safety. If there is uncertainty in performing this as the tank owner, a qualified individual or professional should be sought out.

For more on this, see our post on How to Select and Install a Water Storage Tank.

41. Where is the best place to keep a water tank?

The best place to keep a water tank may depend on the select type of tank. Inside a structure is best, if possible as an option, as it limits temperature fluctuations as well as the extent of sunlight exposure for algae growth. For outside water tanks, it is often best to keep them in shaded locations such as within sheds, barns, beneath trees, roof overhangs, and also on the northern side of structures as this will limit the amount and duration of direct sunlight. 

42. How do I properly tighten the bulkhead fitting?

Tightening a bulkhead fitting is sometimes needed over time as it can loosen during normal use or is needed whenever installing a new bulkhead or replacing an existing one. To properly tighten a bulkhead fitting, hand tighten the bulkhead locknut then perform an additional 1/4 to 1/2 turn. It is important to not overtighten a bulkhead as it can damage the seal and cause the fitting to leak.

43. Is it okay to leave a plastic water tank outside in freezing temperatures? How about with water in the tank?

Yes, cold temperatures do not affect or damage a polyethylene water tank. Therefore, it is okay to leave a plastic water tank outside in freezing temperatures. The only concern with freezing temperatures and poly water tanks is whenever water is stored inside the tank. As long as there is enough extra space to allow the water to expand as it freezes, it is okay to leave water in the tank when temperatures are below freezing. 

Water as a fluid will expand while it freezes from a liquid to a solid, meaning the amount of space the water occupies will increase. Without ample room to allow the water to freeze and expand, the freezing water can press against the fitting(s) and/or lid and potentially damage these connections. If this happens and the lid or bulkhead fitting becomes damaged, they can be replaced.

44. How do I keep water from freezing in a water tank?

There are five options that can help keep water from freezing in a water tank.

  1. Install an aeration pump. Installing an aeration pump to keep the water in the tank moving can help prevent freezing. Water that is actively moving takes more time and/or colder temperatures to freeze than stationary water. However, this may not be sufficient for larger volume water tanks. 
  2. Cover the water tank to insulate the container against the cold. This can be done in a number of ways but will depend on the size of the tank and feasibility. Example coverings can include blankets, tarps, water heater insulation, and insulation wrap used in structures. Even hay bales could potentially be used to cover a water tank.
  3. Use electric tank heaters. Heaters designed for barrels, drums or IBC totes can be used on poly water tanks to heat the stored water and prevent freezing. Some companies manufacture tank heating elements designed for poly water tanks.
  4. Move the water tank inside a shelter. Moving the water tank within a garage, shed, barn, etc. during the winter can help protect the tank from the cold. However, this may not be feasible if the tank is connected to a plumbing system, is too large to move without proper equipment, or the loss of the water due to draining is not acceptable.
  5. Drain enough water from the tank to allow room for the freezing water to expand. While not an option to keep the water from freezing, it is an acceptable option to protect the tank against any potential damage that could occur during freezing.

The maximum recommended service temperature for polyethylene water tanks is 120°F for internal water storage conditions. Although high density polyethylene (HDPE, what most poly water tanks are made from) is rated to handle temperature extremes up to 130°F for short periods, temperatures continually above 120°F will stress the limits of safety for most standard poly water tanks. 

Ambient temperatures are not as much of a concern for a water tank as the internal temperature of stored materials. Due to the regular day and night cycle of warming and cooling, it is unlikely for outdoor temperatures above 100°F to cause the stored water to warm to a point where it could potentially weaken the water tank durability.

46. How long do plastic water tanks last?

A high quality, well-maintained and ideally installed polyethylene water tank can last as long as 20 years, if not longer. However, there isn’t a set standard for poly water tank service life or anything but a general approximation of how long they will last, with most suggesting anywhere from 3 years to 20+ years. 

The highest quality poly water tanks will be made by the industry’s most reputable manufacturers using premium, virgin grade resin molded with ultraviolet (UV) stabilizing compounds to protect the plastic against sunlight damage. 

Some of the industry’s best water tank manufacturers include Norwesco, Snyder, Enduraplas, Ace Roto-Mold, and Dura-Cast.

A well-maintained poly tank will undergo regular cleaning and inspection schedules to ensure the tank remains in top performing state. An ideally installed water tank will be in a location that limits or prevents sunlight exposure, helps to maintain the stored water temperature, and maintains a structurally sound foundation that fully supports the base of the tank and does not erode over time. These considerations will help promote an overall healthier tank and maximize the water tank’s service life.

47. Can any plastic water tank be buried for use underground?

No, it is not acceptable or approved to use any above ground plastic water tank for underground installation. 

Specifically designed underground water tanks (often called cisterns) are engineered, certified and approved for burial as they have been made to withstand the increased, extra load weight stress that accompanies being installed beneath the earth’s surface. 

Some companies and DIYers support partial burial, such as only the base of an aboveground tank. However, we do not recommend this practice and doing so can actually void your water tank’s manufacturer’s warranty.

48. What is the certified maximum burial depth for an underground polyethylene water tank?

The maximum burial depth for an underground polyethylene water tank (cistern) will vary on the storage tank style, gallon capacity as well as any local government regulations pertaining to soil conditions, groundwater table height, and building codes. 

In general, underground water tanks are engineered to withstand a maximum load weight of soil atop the tank on burial – this directly determines a cistern’s maximum burial depth. Cisterns are manufactured in different designs and volume capacities that will affect their maximum vertical load rating in pounds per square foot. 

Check with the distributor or manufacturer to verify a cistern’s max vertical weight load and its certified max burial depth as most manufacturers provide an installation guide for their underground tanks.

49. Is it okay to drive over the spot where an underground water tank is installed? Can I pave over an underground tank?

While it may be okay in some installations, for most cases it is not recommended to drive over the spot where an underground water tank has been buried. Underground water tanks have not been engineered to withstand the weight load and force caused by a vehicle at surface level driving over the installed tank. This can cause an excessive weight load balance delivered to the buried tank that can damage the tank’s plumbing setup or cause the tank to crack. 

Underground water tanks are usually not paved over due to regular maintenance and/or usage interaction requirements. 

50. How is a water tank shipped and delivered?

Most often and due to their size, polyethylene water tanks are shipped and delivered by independent freight transport and logistics companies on flatbed trucks or in semi-truck trailers. 

These freight companies are hired to handle the transit of the water tank at the behest of the company selling the water tank. This means they are two separate companies – the company selling the water tank differs from the company that ships and delivers it – and this means any questions, comments, concerns or problems must be directed to the correct party. 

The company selling the water tank is not responsible for problems that arise during shipping, just as the freight company is not responsible for a manufacturer defect. 

For more on this, see our post on How to Order and Receive a Poly Storage Tank. 

51. How long does it take to receive my water tank after purchase?

Shipping times for water tanks will vary. They can be affected by the freight origination point, freight carrier, potential backorder delays and other unforeseeable concerns. 

On average, the shipping time for a water tank can take anywhere from 2 to 12 weeks after any potential lead time on the manufacture of the water tank.

52. What does a water tank cost?

The cost of purchasing a water tank will include the purchase price of the water tank itself, shipping and handling costs, as well as any additional costs with installing the water tank, which can include the foundation, plumbing and any additional accessories as needed for the application.

53. What is the best way to store water long term in a poly water tank?

Water is best stored long term in polyethylene water tanks when the water is kept in a cool, temperature-stable, dark location away from sunlight. Temperatures between 50°F to 70°F are recommended. Underground water tanks make a great choice for long term water storage.

54. How do I clean or purify my water for drinking use? How to keep water fresh in a storage tank?

Using the proper amount of household bleach is a common method to purify water in a storage tank using a chemical additive. Several options exist for purifying the water in a storage tank to make the water safe for human use. They include:

1: Chlorine – Use of chlorine is a highly effective method to remove disease-causing pathogens and purify water to potable quality standards. Basic household bleach is the most used and recommended method for disinfecting a water supply and supported by government research and approvals. Bleach products that are scented, with additives for colored clothes, labeled as “splash less” or with additional cleaners should not be used. 

Use chlorine bleach that is listed on the label to contain 5% to 9% concentration of sodium hypochlorite (the active ingredient in bleach and source of chlorine). Add 0.5 milliliters (mL) of chlorine bleach per gallon of water to be disinfected. In example, for a 250 gallon rainwater harvest tank, the recommended amount of bleach is 125 mL or about ½ cup or about 4.25 ounces.

After treating a water tank with chlorine bleach, wait at least 24 hours before using the water for drinking, cooking, bathing, or cleaning to ensure any potentially harmful bacteria, parasites, viruses have been eliminated. Source reference and extra information: NSW Health

2: Iodine – The iodine treatment method is often reserved for smaller water volumes and is commonly added in tablet form. The use of iodine in disinfection and water purification is not recommended for pregnant women, individuals with thyroid concerns, or known sensitivity to iodine due to potential complications. Iodine type disinfection is not recommended for extended use and better reserved for emergency type situations.

3: Boiling – Boiling water can be used to disinfect water drawn from a storage tank prior to its use. Water that is boiled for disinfection should be brought to a rolling boil for at least 1 minute. Boiling water is effective in killing and removing viruses, parasites and bacteria.

4: Filter – There are various filtration options available for water purification, some are more effective than others in what they filter out of the water. Some filters are designed for installation before a storage tank to filter the water before it enters the tank. Other filters are designed for filtration prior to use. Filters that meet NSF 53 and 58 certifications will effectively remove parasites. Reverse osmosis filters are most effective in removing bacteria, viruses, and harmful metals. Combining several filters in a multi-stage filtration system can clean and purify water and rainwater to meet and exceed drinking quality standards without the need to use chemicals.

5. Ultraviolet Light – Ultraviolet light systems incorporate UV emitting bulbs to transmit UV energy rays that can disable bacteria, parasites, and disable. UV light systems may not be effective in eliminating all pathogens – and this can be dependent on water quality and clarity – and the specific manufacturer’s recommendations and usage guidelines should always be followed. If use recommendations are followed and UV light is paired with a filtration system that clarifies water turbidity, UV disinfection can be 99.9% effective.

See this resource from the CDC for more details on water purification and treatment.

55. How long will purified water remain good for drinking in a poly water tank?

Most recommendations say purified water will remain okay to drink for at least six months in a sealed, undisturbed container stored in a cool, dark location. However, this depends on the extent of purification and methods used to purify the water in the tank. 

Commercially prepared and sealed water containers, (water bottles, gallon jugs, etc.), are said to be good indefinitely if they remain sealed. 

Water tanks and containers that have been personally filled and properly treated with a 5.25% sodium hypochlorite solution (bleach) are said to be good for up to 5 years, if not disturbed. 

For personally filled containers not treated with bleach and are perhaps drawn from on occasion are advised with a maximum recommendation of six to 12 months. After this time, the water should be cycled and replaced. 

56. How much water should be stored for a family in case of an emergency?

The minimum recommendations are to keep 1 gallon of water per person per day for water use in an emergency, disaster or water shortage type situation. If animals or pets are included, keep 1 gallon of water per day for them as well. So, at least 1 gallon of water for every person in a family or otherwise accounted for per day. Water use includes drinking, food preparation and hygiene needs. Emergency water tanks are an excellent choice for water prepping and have been specifically made for this use.

Add 1 gallon of water per person and multiply by the number of days you plan to be prepared for in case of emergency water needs. In an example, a family of 4 would need 4 gallons of water a day, and if preparing for a water shortage event expected to last 1 month, the family would approximately need 120 gallons, at least. Information source: The U.S. Centers for Disease Control and Prevention (CDC).

57. What type of plumbing should I use with my water tank?

Common schedule 40 PVC pipe is frequently used with water tanks for plumbing applications. If PVC is chosen for use, ensure the product is manufactured to be lead-free and meet ANSI/NSF 61 and 14 certifications for potable water handling. This recommendation holds even if the water tank will be for non-potable applications. 

Most poly water tanks feature a female NPT threaded bulkhead with sizes ranging from 1/2” to 4”. Use of the same size diameter, threaded pipe is recommended. 

Consider using a PVC true union ball valve to control the on/off release of water from the tank. A true union ball valve will allow the plumbing to be easily disassembled if ever needed for maintenance or relocating the tank.

The use of expansion joints and flexible connections when joining plumbing to tank fittings is recommended to account for the daily expanding and contracting poly water tanks experience due to heating and cooling arising from ambient temperature fluctuations. The rate and extent of expansion / contraction of polyethylene will vary by tank engineering specifics as well as the amount of temperature change and direct sunlight exposure. The amount a poly water tank expands and contracts may be slight and unperceived by the human eye, but is enough to cause extraneous stress to the tank and fittings, which can result in damage and leaks.

58. Are the water tanks listed for sale and available online FDA approved?

Yes and no. For poly water tanks, it is the materials used to manufacture the polyethylene tank that are approved by the Food and Drug Administration (FDA) not the water tank itself. The water tank itself and the manufacturing facility is approved to meet the standards for drinking water use through certifications from the National Sanitation Foundation (NSF 61) and the American National Standards Institute (ANSI). Water tank products listed with ANSI/NSF Standard 61 certifications and listed as manufactured from FDA food grade plastic are approved for use with drinking water.

All water tank products listed in our potable water tanks category are certified manufactured from FDA approved materials and ANSI/NSF guaranteed for drinking water applications.

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