Can I Put Water In A Critter Tank? And Why You Shouldn’t Do It

Can I Put Water In A Critter Tank? And Why You Shouldn’t Do It

A critter tank is different from an aquarium. This difference cuts across design, structure, and function. For this reason, many come with a “DO NOT FILL WITH WATER” label. But is it okay to ignore the warning and fill it with water?

This article discusses the answer and offers direct justifications for it. You are guaranteed not to make the mistake of damaging your critter tank, and the reason you shouldn’t do that, after reading this post.


“Critter” is a collective term for animals. They may range from the typical rats and lizards that scratch your ceiling at night to the domestic ones kept as pets like dogs and cats. Typically, critters are animals that humans have tamed as pets. They include hedgehogs, rabbits, dogs, cats, birds, etc.

Depending on the nature of the critters, you may have to get a tank or a cage. A critter cage will fit well for rabbits, birds, squirrels, etc. But you may get a critter tank for your crabs, snakes, and turtles. Amphibians such as frogs, toads, newts, salamanders, and more also do well in critter tanks. Their nature and the characteristics of their natural habitat make them ideal for tanks.

Some of the critter tanks sold in pet stores today are often called “Critter Cage” instead of “Critter Tank,” but that’s not a problem. It is a brand. As long as it is made of glass with the purpose of housing reptiles for display, it might as well be called a critter tank. However, some critter cages are designed to look like iron cells. They are not capable of holding water. These would fall appropriately within the cage description for critters that may not be reptiles.

Putting Water in a Critter Tank

Often when you go to the pet store for a critter tank, most of them have a “Do not fill with water” label attached to the tank. The question that arises with the “Do Not Fill with Water” sign is, can you put water in a critter tank? 

No, you can’t! Critter tanks are not made to hold water like breeder aquariums. The “Do not fill with water” label was attached to the critter tank for a reason.

Why You Should Not Put Water in a Critter Tank

Why You Should Not Put Water in a Critter Tank

There are two main reasons you should not put water in your critter tanks. First, its structure cannot hold water, and secondly, it was built for a purpose that does not support filling it with water. These reasons are discussed in detail below.

Structure and Design of the Critter Tank

The reason is that critter tanks have thinner glass and could break if you fill them with water. They come in various sizes, which include the 5-gallon, 10-gallon, or 20-gallon critter tanks. They are typically built to feature parts that ease access and improve the safety of handling the reptile. Most of them come with a small opening for passing food in for the reptile. But the gaps are never big enough for the reptiles to escape. They also come with wiring ports to neatly channel heating systems. For obvious reasons, the designs are usually delicate; critter tanks are display tanks, not breeding or cultivating tanks.

A comparison with aquariums will better help you appreciate the difference in design and structure. Unlike aquariums made with strong reinforced glass and durable sealants to hold water, critter tanks are made with thin glass. This comparison is essential because water is heavy and has a force so powerful that it wears away rocks. You could end up with a damaged critter tank if you put water in it. 

The function of the Critter Tank

Critter tanks are made to display your reptiles or other critters you want to display. They usually come with lockable mesh tops that slide in and out. This is to prevent escape as some reptiles, especially snakes, are known as escape artists. The purpose is to display. 

In comparison, aquariums come with a more sophisticated system to serve the function of breeding, cultivation, or long-term keeping. They are not explicitly designed for display functions. Putting water in your critter tank will defeat the function of the tank. It will ultimately lead to damaging the critter tank whether you fill it halfway or full.


If the manufacturers do not recommend filling it with water, do not fill it with water. The recommendation stems from the nature of materials used to build the critter tank.

Some so-called pet experts and hobbyists may recommend filling it halfway. That would be pushing your luck. At best, minimal water is enough, but this would only be appropriate for critters like frogs and turtles. 

What Can You Do?

It is not out of place if you are new to the practice of keeping reptiles and may have made the mistake of going for a critter tank instead of a fully equipped aquarium. Probably, this is why you have taken to the internet to explore the possibility of having the critter tank serve as a tank that can hold water for your reptiles. Here are a few suggestions to help you deal with the situation.

Change It or Trade It in for an Aquarium

This option could still be feasible if you realize early in the first few days of the purchase that you should have gone for a proper aquarium instead of a critter tank. Some pet stores may offer a return policy. Check to see if you are still within the time frame. If you are, check for the conditions to see if you can satisfy the return policy requirements. If yes, you can take the critter tank back and explore the option of a refund or a replacement with an aquarium.

Alternatively, you could take it back to the pet store and ask to exchange it and some money for a proper aquarium. It would be best to return it in the best condition possible as the pet store is unlikely to consider your offer if the critter tank has been damaged in any way.

Offer it for Sale

Museums and other possible exhibition facilities such as wildlife research institutions often display species in critter cages. They fit the purpose of the exhibition better than a fully equipped aquarium. You could offer them your barely used critter tank for a reasonable price. You get to have a significant portion of your money back, and the critter tank gets to where it is needed.

Bottom line

Critter tanks are meant for displaying your reptiles. This purpose affects the designs and structure of the tank. They are not built to hold water, whether half or full tank. It would be best not to put water in your critter tank. If you do, you risk destroying the tank.