A common 10-gallon reptile aquarium can accommodate a single adult axolotl, but due to the large amount of waste produced by these messy creatures, a 20-gallon aquarium is a safer choice. Axolotls do not emerge from the water, so a land area would go unused. Fill the aquarium to the depth of your choice, but it will be easier to maintain good water parameters when the aquarium is filled, as you would for aquarium fish. A lid or aquarium hood should be kept in place at all times because axolotls have been known to jump out of their aquariums.
A filter will help maintain safe water parameters. The best choice is an external canister filter, but ensure the water outlet to the aquarium is fitted with a spray bar or other flow-spreading outlet. This is necessary because axolotls do not tolerate distinct water flow like fish. Axolotls that live in a noticeable water flow for a few months will go off food and develop stress-related diseases. Lack of appetite and forward-curled gills are usually a sign of stress from too much water flow.