When housing tentacled snakes, it helps to think of them more as fish than reptiles. They are completely aquatic, coming to the water’s surface primarily to breathe. Aquariums are the best housing choice because they are designed to hold water and offer the best viewing opportunities.
A single adult tentacled snake can be kept in a 20-gallon “long” aquarium, although I have found this species does best when kept in small groups. Up to four can be kept in a standard 55- to 60-gallon aquarium. A 125-gallon aquarium can comfortably house up to seven tentacled snakes. The surface area in the aquarium is more important than its height, but the aquarium should be tall enough to allow both a proper water depth and clearance between the water and the aquarium top, as tentacled snakes are good escape artists. A haul-out area can be provided, but in the nearly six years I have worked with tentacled snakes, I have never known them to use one. The ideal water depth appears to be between 6 and 12 inches. Provide plenty of hiding places and anchoring sites. Tentacled snakes use their prehensile tails to anchor themselves, much like a seahorse. Driftwood, stones, logs and aquatic plants (live or artificial) can be used to create the ideal habitat.