Axolotl care guide: tank, temperature, substrate and diet

Temperature is the thing that kills axolotls

If you remember one thing, make it this. Axolotls (Ambystoma mexicanum) are cold-water animals from high-altitude lakes in Mexico. Their ideal range is 16-18C (60-64F), and they tolerate up to around 20C. Push past 22-24C and they go off their food, their slime coat suffers, fungal and bacterial infections set in, and prolonged heat is simply fatal.

This means no heater - the opposite of a tropical tank. In a cool room you may need nothing. In a warm room or a hot climate, keeping the water cold is the real challenge and may require an aquarium chiller, or at least a clip-on fan blowing across the surface and frozen water bottles in a pinch. Be honest with yourself about your room temperature before buying an axolotl - this is where most go wrong.

The substrate rule: bare bottom or fine sand

Axolotls feed by creating suction, vacuuming up food and anything sitting near it. Give them gravel or small stones and they will swallow it, and swallowed gravel causes impaction - a blockage of the gut that is frequently fatal and hard to treat.

So the only safe choices are:

• Bare glass bottom - safest of all, easiest to keep clean, and fine for the animal even if it looks plain.
• Fine aquarium sand - looks natural, gives them grip (they slip on bare glass), and passes harmlessly through the gut if a little is swallowed.

Never use gravel, pebbles, or small decorative stones in an axolotl tank. See our substrate options guide for how sand compares to other choices.

Tank size and setup

• Size: at least 75 L (20 US gallons) for a single adult; they grow to 20-30 cm. Floor space beats height - they are bottom-dwellers - so choose a long, wide tank.
• Filtration: they are messy, so you need good filtration, but they dislike strong flow. A sponge filter or a baffled hang-on-back/canister is ideal. Strong current stresses them and can curl their gills forward.
• Hides and cover: provide caves, plants (real or silk) and shade. Axolotls have no eyelids and dislike bright light, so keep lighting dim and give them somewhere to retreat. See our axolotl plant guide for which live plants actually survive the digging and the cold.
• Lid: keep it covered - they can and do climb or jump out.

Cycling the tank: treat them as more sensitive than fish, not less

An axolotl tank needs the same nitrogen cycle as any other aquarium - a colony of bacteria that converts fish (or in this case, axolotl) waste from toxic ammonia into nitrite and then into much less harmful nitrate. What's different is the margin for error. Axolotls breathe partly through their skin and gills, both of which are in constant, unprotected contact with the water, so ammonia and nitrite exposure hits them faster and harder than it hits most fish. Run a full fishless cycle before the axolotl goes anywhere near the tank - don't cycle with the animal in it, and don't trust a "it's probably fine by now" guess. Test until ammonia and nitrite both read zero on repeat checks, not once.

Handling: why the answer is usually "don't"

Axolotls are covered in a protective slime coat that guards against infection, and it comes off easily on dry skin, paper towels, or a net dragged across their body. Losing enough of it is a real infection risk, not a cosmetic issue. In practice:

• Don't handle unless you have to. Moving tanks, water changes, and health checks are the main legitimate reasons - not showing them off.
• If you must move one, scoop with a wide, soft net or a cup with water in it rather than lifting them into the air. Never pick one up with dry hands.
• If skin contact is unavoidable, wet your hands first with dechlorinated tank water and support the body - don't grip a limb or the tail.

Do axolotls need land? (No - and this trips people up)

Unlike most salamanders and newts, axolotls are neotenic: they keep their larval, fully aquatic form - external gills, aquatic tail, no lungs-only lifestyle - for their entire life instead of metamorphosing onto land. A healthy axolotl in a proper cold-water setup should never need to leave the water, and land access in the enclosure serves no purpose for a normal pet. This is worth knowing because a lot of generic "amphibian" or "salamander" care advice assumes a land phase that simply doesn't apply here.

Occasionally an axolotl does metamorphose anyway - losing its gills and developing lungs and drier, thicker skin, effectively becoming a terrestrial salamander. This is not a fun surprise: it's usually triggered by chronic stress, prolonged warm water, or (rarely) iodine exposure, it shortens a healthy axolotl's lifespan considerably, and an animal that morphs needs an entirely different, land-based setup almost immediately. It's a genuine reason to take the temperature rule seriously rather than a curiosity.

Regeneration: impressive, but not a free pass

Axolotls really can regrow lost limbs, tails, and even parts of the spinal cord and organs, which is exactly why they're a staple of regeneration research. But "it'll grow back" isn't a reason to be casual about injuries - regrowing a limb takes weeks to months, uses real energy reserves, and the open wound is an infection risk for all of that time. Treat any bite, nip, or injury as something to address (clean water, isolate if another axolotl caused it, monitor closely), not something to shrug off because the anatomy is forgiving.

Water quality and parameters

Axolotls have permeable skin and delicate external gills, so they are sensitive to poor water - in some ways more so than fish. The tank must be fully cycled before they go in, and the water dechlorinated.

• Ammonia 0, nitrite 0 - non-negotiable; both are highly toxic to them.
• Nitrate low - keep it modest with regular water changes (roughly 20% weekly is a good starting habit).
• pH 7.4-7.6 - neutral to slightly alkaline.
• Moderate hardness - very soft water is not ideal; a little mineral content keeps them healthy.

Use a liquid test kit and stay on top of it, especially while the tank is young.

Diet

Axolotls are pure carnivores. Good staples:

• Earthworms / nightcrawlers - the gold-standard staple; nutritious and well digested. Cut to size for smaller animals.
• Sinking carnivore or axolotl pellets - convenient and balanced.
• Bloodworms and blackworms - good supplements, especially for juveniles.

Avoid feeder fish. They carry parasites and disease, can introduce thiaminase, and pose a choking risk. Feed adults every 2-3 days and juveniles daily, and remove anything uneaten to protect water quality.

Tankmates: keep it simple

The honest answer is that axolotls do best alone. They will eat any fish small enough to fit in their mouth, and fish - even small ones - peck at their feathery gills, causing injury and infection. If you want more than one axolotl, keep them at a similar size in a tank large enough for each, and watch juveniles closely, as young axolotls will nip each other's limbs and gills (limbs regenerate, but it is still stress and infection risk). See our full axolotl tank mates guide for the complete breakdown, including the one case (large, hard-shelled snails) that's genuinely lower-risk.

What a healthy axolotl looks like before you buy one

Whether you're at a shop, an expo, or buying from a breeder, check the animal itself, not just the price:

• Gills fanned out and moving, not clamped flat or curled tightly against the head - clamped gills are a stress or water-quality sign in the seller's own tank.
• Alert and responsive - tracking movement, reacting to food, not sitting motionless on its side.
• Straight spine and tail, four full limbs (or limbs visibly regenerating cleanly, which is normal and not a dealbreaker on its own).
• No red streaking on the legs or belly, no fuzzy white patches, no obvious sores.
• Ask about the water it's coming from - a seller who can't tell you the temperature is a seller who probably isn't keeping it cold enough.

If something looks off, it's fine to walk away. An axolotl bought on impulse from a stressed, overheated display tank is starting its life already behind.

Related guides

• Axolotl SOS - symptom checker
• Can axolotls live with fish?
• Best plants for an axolotl tank
• Axolotl morphs and colours
• The real cost of keeping an axolotl
• The nitrogen cycle (cycle before adding livestock)
• Understanding water parameters
• Aquarium substrate options
• When your tank is too warm