Axolotl Tank Setup Guide | Equipment & Environment

1. Tank Size and Dimensions

Axolotls are large, heavy-bodied amphibians that can reach 10-14 inches in length. They produce a massive bioload (waste), which requires a significant volume of water to dilute.

Minimum for One Axolotl: 29-gallon long or 40-gallon breeder tank.
For Two Axolotls: 40-gallon breeder minimum, 55-gallon preferred.
Footprint matters: Axolotls are bottom-dwellers. A long, wide tank (like a 40-breeder) is vastly superior to a tall, narrow tank, as it provides more floor space for walking.

2. Temperature Control (The Most Critical Factor)

The 60°F - 68°F Rule

Axolotls are cold-water amphibians native to high-altitude lakes in Mexico. Their ideal temperature range is strictly 60°F to 68°F (15°C to 20°C).

Temperatures exceeding 68°F induce severe physiological stress, suppress their immune system, and rapidly lead to fungal infections. Temperatures reaching 75°F or higher are often fatal within days.

Cooling Solutions:

Aquarium Chillers: The most reliable and effective method. Essential if your home ambient temperature regularly exceeds 70°F.
Clip-on Cooling Fans: Can lower the water temperature by 2-4°F through evaporative cooling. Requires frequent top-offs.
Frozen Water Bottles: A temporary emergency measure during heatwaves, but causes dangerous temperature fluctuations. Do not rely on this long-term.

3. Filtration and Flow

Axolotls require heavy filtration due to their bioload, but they are highly stressed by strong water currents. Their native lakes are relatively still.

Sponge Filters: Excellent for biological filtration and provide gentle flow. Highly recommended.
Canister Filters: Provide superior mechanical and biological filtration, but the outflow must be baffled (using a spray bar or pointing it at the glass) to reduce current.
Hang-on-Back (HOB) Filters: Acceptable, but the waterfall effect can create too much current. Keep the water level high to minimize the drop.

4. Substrate and Decor

The Danger of Impaction

NEVER use aquarium gravel or small stones. Axolotls eat by creating a sudden vacuum, inhaling their prey along with anything nearby. Gravel will be swallowed, causing fatal intestinal blockages (impaction).

Safe Substrates:

Bare Bottom: The safest option, especially for juveniles under 5 inches. Easy to clean.
Fine Sand: Safe for adults (over 5-6 inches). The sand grains are small enough to pass safely through their digestive tract.
Large River Rocks: Must be significantly larger than the axolotl's head (at least 2-3 times larger).

Decor: Provide plenty of hides (PVC pipes, terracotta pots, large silk plants). Axolotls do not have eyelids and are sensitive to bright light, so they need dark places to retreat.