What Size Tank Does an Axolotl Need?

Choosing the right tank size is one of the most important decisions you will make as an axolotl keeper. Too small and your axolotl will be stressed, water quality will deteriorate quickly, and health problems will follow.

Minimum Tank Sizes

Rule of thumb: 75 liters (20 gallons) for the first axolotl, plus 40 liters (10 gallons) for each additional one.

Why Floor Space Matters More Than Depth

Axolotls are bottom dwellers. They spend 90% of their time walking along the substrate and resting in hides. They rarely swim to the surface except to gulp air occasionally.

This means horizontal floor space is more valuable than vertical water depth. A long, shallow tank is ideal:

• 20-gallon long (76 x 30 x 30 cm): excellent for one axolotl
• 40-gallon breeder (91 x 46 x 40 cm): excellent for two axolotls
• Standard tall tanks waste vertical space that axolotls do not use

Minimum water depth should be at least 30 cm (12 inches) so the axolotl can swim comfortably when it wants to, but 45 cm or less is fine.

Why Bigger Is Always Better

Larger tanks offer significant advantages:

• Water quality stability: more water volume means slower parameter changes. A 40-gallon tank is much more forgiving of a missed water change than a 20-gallon.
• Temperature stability: larger water volumes resist temperature swings from room temperature changes.
• More space for hides: multiple hiding spots reduce stress and territorial behavior.
• Easier maintenance: counterintuitively, larger tanks are often easier to maintain because the water parameters are more stable.

Common Tank Options

Tanks to Avoid

• Bowls or small containers: completely unsuitable, no filtration possible
• Tall hex tanks: wasted vertical space, small footprint
• Uncovered tanks: axolotls can and will escape
• Tanks with sharp edges or seams inside: can injure delicate skin