Tank Size Is a Health Decision
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.
Tank size is a key part of any complete tank setup. The rule is simple: 75 liters (20 gallons) for the first axolotl, plus 40 liters (10 gallons) for each additional one.
Minimum and Recommended Tank Sizes
| Axolotls | Minimum Size | Recommended Size |
|---|---|---|
| 1 | 75L / 20 gal | 100L / 25 gal |
| 2 | 115L / 30 gal | 150L / 40 gal |
| 3 | 150L / 40 gal | 190L / 50 gal |
| 4 | 190L / 50 gal | 225L / 60 gal |
1
Minimum Size : 75L / 20 gal
Recommended Size : 100L / 25 gal
2
Minimum Size : 115L / 30 gal
Recommended Size : 150L / 40 gal
3
Minimum Size : 150L / 40 gal
Recommended Size : 190L / 50 gal
4
Minimum Size : 190L / 50 gal
Recommended Size : 225L / 60 gal
Why Floor Space Matters More Than Depth
Why Bigger Is Always Better
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, protecting your axolotl from thermal stress.
More space for hides
Multiple hiding spots reduce stress and territorial behavior. Each axolotl should have at least one dedicated hide.
Easier maintenance
Counterintuitively, larger tanks are often easier to maintain because the water parameters are more stable.
Common Tank Options Compared
| Tank | Dimensions (cm) | Volume | Best For |
|---|---|---|---|
| 20 gal long | 76 x 30 x 30 | 75L | 1 axolotl (minimum) |
| 29 gal | 76 x 30 x 45 | 110L | 1 axolotl (comfortable) |
| 40 gal breeder | 91 x 46 x 40 | 150L | 2 axolotls |
| 55 gal | 122 x 33 x 51 | 210L | 2-3 axolotls |
| 75 gal | 122 x 46 x 51 | 285L | 3-4 axolotls |
20 gal long
Dimensions (cm) : 76 x 30 x 30
Volume : 75L
Best For : 1 axolotl (minimum)
29 gal
Dimensions (cm) : 76 x 30 x 45
Volume : 110L
Best For : 1 axolotl (comfortable)
40 gal breeder
Dimensions (cm) : 91 x 46 x 40
Volume : 150L
Best For : 2 axolotls
55 gal
Dimensions (cm) : 122 x 33 x 51
Volume : 210L
Best For : 2-3 axolotls
75 gal
Dimensions (cm) : 122 x 46 x 51
Volume : 285L
Best For : 3-4 axolotls
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 their delicate skin.
The 20-Gallon Long Sweet Spot
The 20-gallon long (76 x 30 x 30 cm) is the most popular choice for a single axolotl. It provides excellent floor space, fits on standard furniture, and is widely available at pet stores. If you plan to keep two axolotls, start with a 40-gallon breeder (91 x 46 x 40 cm) to avoid upgrading later.
Ready to set up your tank?
Once you have chosen the right tank size, the next step is selecting a safe substrate and proper filtration.
Tank Size Calculator
Enter your number of axolotls for the right tank size
Frequently Asked Questions
Frequently Asked Questions
Can an axolotl live in a 10-gallon tank?
Is a 20-gallon long or tall better for axolotls?
How many axolotls can I keep in a 40-gallon tank?
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