Advertisement A few piccies of my little gang of land hermit crabs (four Coenobita Clypeatus and four Coenobita Compressus) First off, the Crabitat - a glass tank 24" long x 15" wide x 9" deep. The lid is made from a sheet of perspex cut to size, and held in place with strips of stick-on velcro. The substrate in the tank is a mixture of 3 parts aquarium sand to 2 parts coconut fibre (eco-earth) to 1/2 part aquarium gravel and 1/2 part chopped sphagnum moss. This allows the crabs to burrow (they do this for entertainment and for safety when moulting), but does not become waterlogged easily - it is not as susceptible to mould as pure peat or eco-earth might be, but holds water better and allows more even evaporation than pure sand. The substrate is two inches deep at one end of the tank, rising to nearly 5 inches deep at the opposite end.