What is the Right Tank Size For an Axolotl?

If you are thinking about getting an axolotl, one of the most important decisions you will make is choosing the right tank. These adorable aquatic salamanders spend their entire lives in water, so their tank is literally their whole world. Getting the size right from the start will save you headaches down the road and keep your axolotl healthy and happy.

The short answer is that a single axolotl needs at least a 20 gallon long tank. But there is a lot more to it than just picking up any old 20 gallon aquarium. The shape of the tank, the water depth, and how many axolotls you plan to keep all play a role in choosing the right setup.

Why Tank Size Matters So Much for Axolotls

Axolotls are messier than most people expect. They produce a lot of waste, and in a tank that is too small, that waste builds up fast. Ammonia levels spike, the water gets cloudy, and your axolotl’s health suffers. A bigger tank means more water volume, which dilutes waste and keeps water parameters more stable between cleanings.

Space also affects your axolotl’s stress levels. In a cramped tank, they cannot move around comfortably, and stress can lead to a whole host of health problems including loss of appetite, gill deterioration, and a weakened immune system. Axolotls may look like they just sit in one spot all day, but they actually do walk around and explore, especially at night.

Water temperature is another factor. Axolotls need cool water, ideally between 60 and 68 degrees Fahrenheit. Smaller tanks heat up faster and are harder to keep cool, especially in the summer. A larger volume of water is much more resistant to temperature swings, which is better for your axolotl’s overall well being.

Minimum Tank Size for One Axolotl

For a single adult axolotl, you need at least a 20 gallon long tank. The “long” part is important here. Axolotls are bottom dwellers, so they care more about floor space than water depth. A 20 gallon long tank measures about 30 inches long by 12 inches wide, which gives your axolotl a nice stretch of floor to walk along.

A standard 20 gallon tall tank is not a great choice even though it holds the same amount of water. The tall version is narrower and deeper, which means less floor space and more unused vertical water that your axolotl will never really use. Always go for length and width over height.

That said, bigger is always better when it comes to axolotl tanks. If you can swing a 29 gallon or 40 gallon breeder tank for a single axolotl, your pet will be much happier and you will have an easier time maintaining water quality. Think of 20 gallons as the minimum, not the ideal.

Tank Size for Multiple Axolotls

If you want to keep more than one axolotl, you need to plan for extra space. The general rule is to add 10 gallons for each additional axolotl. So two axolotls need at least 30 gallons, three need 40 gallons, and so on.

A 40 gallon breeder tank is one of the most popular choices for keeping two axolotls. It has a nice wide footprint that gives both animals plenty of room to explore without constantly bumping into each other. Axolotls can be a bit nippy, especially when they are young, so giving them enough space to stay out of each other’s way helps prevent injuries.

Keep in mind that even with the right tank size, you should never house axolotls of very different sizes together. A larger axolotl may try to eat a smaller one. Only keep axolotls together if they are roughly the same size, and always have a backup tank ready in case you need to separate them.

Tank Shape and Dimensions to Look For

As mentioned, floor space is more important than depth for axolotls. Here are some popular tank sizes and how they work for axolotl keeping.

A 20 gallon long (30 x 12 x 12 inches) is the minimum for one axolotl and a solid starter tank. A 29 gallon (30 x 12 x 18 inches) gives a little more water volume with the same footprint, which helps with water quality. A 40 gallon breeder (36 x 18 x 16 inches) is excellent for one or two axolotls and is the most recommended size by experienced keepers.

Water depth should be at least twice the length of your axolotl. Since adults can reach 10 to 12 inches, you want a minimum water depth of about 12 inches. Anything deeper is fine, just make sure there is not such a strong current that your axolotl struggles to reach the surface when it needs to gulp air.

Setting Up the Tank Properly

Getting the right size tank is only half the battle. How you set it up matters a lot too. Axolotls have specific needs that are different from tropical fish, so do not just treat your axolotl tank like a regular aquarium.

For substrate, you have two main options. Bare bottom tanks are the easiest to clean and safest for axolotls. Fine sand is the other popular choice because axolotls can pass it through their digestive system if they accidentally swallow some. Never use gravel because axolotls will eat the stones and can get a fatal impaction.

Filtration is essential, but you need to be careful about water flow. Axolotls do not like strong currents. A sponge filter is the most axolotl friendly option because it provides gentle filtration without creating a lot of water movement. If you use a hang on back filter, baffle the output so it does not create a strong stream.

Add plenty of hides. Axolotls are shy creatures that feel safest when they have places to tuck themselves away. PVC pipes, terracotta pots, and aquarium safe caves all work well. Having multiple hiding spots helps reduce stress and gives your axolotl options.

Keep the lighting dim. Axolotls do not have eyelids and are sensitive to bright light. Low light or no light is best. If you want to see your axolotl, use a low wattage LED on a timer. Live plants like java fern and anubias can help diffuse light and give the tank a more natural look.

Common Tank Size Mistakes to Avoid

One of the biggest mistakes new axolotl owners make is starting with a 10 gallon tank because it seems easier or cheaper. A 10 gallon tank is simply too small for an adult axolotl. Water quality will be a constant battle, and your axolotl will not have enough room to be comfortable. You will end up upgrading anyway, so save yourself the trouble and start with 20 gallons or more.

Another common mistake is choosing a tall, narrow tank. Some people pick a tank based on how it looks in their living room rather than what works for the animal. Remember that axolotls need floor space, not height. A tall, narrow tank might look elegant, but it is not what your axolotl needs.

Overcrowding is also a problem, especially when people start breeding axolotls. Baby axolotls can be kept in smaller containers temporarily, but they grow fast and need to be separated and given proper space quickly. Plan ahead for where everyone will live before you end up with dozens of baby axolotls and nowhere to put them.

Budgeting for Your Axolotl Tank

Tank cost is a factor for most people, and the good news is that axolotl tanks do not have to be expensive. A basic 20 gallon long tank usually costs between $30 and $50 at most pet stores. A 40 gallon breeder runs between $50 and $100. Dollar per gallon sales at pet stores happen regularly and can cut those prices in half.

Do not forget to budget for a filter, a thermometer, hides, and possibly a cooling solution if you live in a warm climate. The total setup cost for a proper axolotl tank usually falls between $100 and $200, not counting the axolotl itself. It is a worthwhile investment for a pet that can live 10 to 15 years with proper care.