Here are some tips for creating a suitable habitat for an axolotl in an aquarium:

Aquarium size: It is recommended to use an aquarium of 30 gallons (about 110 liters) or more for an axolotl. The larger the aquarium, the better, as axolotls need ample space to swim and move about.

Substrate: It is recommended to use a flexible, non-abrasive floor substrate.

Lighting: Axolotls don't need a lot of light, so dim lighting is sufficient. However, it is important to maintain constant light in the aquarium to maintain a normal day/night cycle.

Water Filtration: It is important to keep aquarium water clean by using a filtration system. You can use an external filter or an internal filter, but make sure it is suitable for the size of the aquarium and the needs of the axolotl.

Temperature: Aquarium water temperature should be maintained between 16 and 20 degrees Celsius. You can use a thermometer to measure the water temperature.

Diet: Axolotls are carnivorous animals and should be fed live foods such as insects and earthworms. You can also give them frozen or dried foods if they are available.

It is important to maintain a clean habitat for your axolotl by regularly changing the water in the aquarium and cleaning up waste. Also, be sure to follow the species-specific needs and consult a veterinarian before caring for your axolotl.