Axolotl Tank Setup: Size, Filter, Substrate & Plants

A properly set up tank is the foundation of axolotl health. Axolotls have specific requirements that differ from tropical fish, so getting the setup right from the start is essential.

Tank Size Requirements

Choose a long tank over a tall one. Axolotls live on the bottom and rarely swim to the surface. A 20-gallon long tank provides more floor space than a standard 20-gallon.

Essential Equipment Checklist

• Tank (minimum 75L/20gal)
• Sponge filter or gentle HOB filter
• Thermometer (digital recommended)
• Water test kit (API Master Test Kit)
• Water conditioner (to remove chlorine)
• Hides (at least 1 per axolotl)
• Fine sand substrate or bare bottom
• Lid/cover
• Optional: chiller or clip-on fan for summer, live plants

Substrate Options

Filtration

Axolotls produce a lot of waste, so biological filtration is essential. However, they hate strong water flow.

Best filter types:

• Sponge filter: the gold standard. Gentle flow, excellent biological filtration, cheap, and easy to maintain. See our filter comparison guide for detailed recommendations.
• Hang-on-back (HOB): works well if you baffle the output to reduce flow.
• Canister filter: excellent for larger tanks, but must be adjusted for gentle output.

Avoid: internal power filters with strong flow, undergravel filters.

Water Parameters

The nitrogen cycle must be completed before adding your axolotl. This typically takes 4-6 weeks. Never add an axolotl to an uncycled tank. See our water parameters guide for detailed ranges and testing advice.

Plants and Decorations

Live plants are beneficial because they help absorb nitrates and provide cover. Good choices include:

• Java fern: hardy, low light, axolotls cannot uproot it
• Anubias: tough leaves, attaches to rocks or wood
• Java moss: provides cover for babies
• Elodea/Anacharis: fast-growing, helps water quality
• Marimo moss balls: low maintenance, axolotls play with them

Avoid sharp decorations that could damage your axolotl’s delicate skin. No rough rocks, sharp plastic plants, or decorations with small holes where limbs can get stuck.

Lighting

Axolotls have no eyelids and are sensitive to bright light. Keep lighting dim or provide plenty of shaded areas. If you grow live plants, use a low-intensity LED on a timer (8-10 hours max). Many keepers use no artificial lighting at all.

Step-by-Step Tank Setup

1. Rinse the tank and substrate thoroughly
2. Place substrate (sand or bare bottom)
3. Install filter and heater/chiller if needed
4. Add decorations and hides
5. Fill with dechlorinated water
6. Plant live plants
7. Start the nitrogen cycle (add ammonia source)
8. Test water daily for 4-6 weeks until cycled
9. Perform a large water change
10. Add your axolotl