Cage Furnishings There are three necessities for furnishing the cage: stuff to climb on, a water bowl and food dish.
Land hermit crabs love to climb and this is a good way to provide some exercise. Choya (or cholla) wood is ideal and can be arranged to allow climbing. Pieces of coral, driftwood, and other types of wood can be used - the reptile section of the pet store is a good place to look for a variety, or check the online hermit crab retailers listed below. Look in the aquarium, reptile and small animals sections of your pet store to find a variety of interesting climbing, basking, and hiding structures that are easy to clean and could be used for hermit crabs. Artificial plants are also a great addition to the crab tank. You can periodically change things around or add different items to provide some variety and interest for the crabs. Some enterprising individuals even use Lego to build climbing structures for their crabs.
Dishes - Water and Food
For food dishes you will want something shallow, sturdy, and easy to clean. Flattened heavy plastic dishes made to look like rocks can be found in the reptile section, or you can use shallow ceramic dishes made for small animals. Some people also use natural sea shells (the flatter half shells) for feeding.
Since all species of hermit crabs should have access to both fresh and salt water you will need two water dishes. They should be big and deep enough to let the crabs get into them if they wish to soak (especially the slat water dish), but easy to get out of and not so deep that drowning is a risk (strawberry hermit crabs should be given a salt pool deep enough to fully submerge themselves in, but for most species it does not need to be that deep). With deeper dishes, smooth river stones or pieces of coral can be used as ramps or steps for the crabs to get out of the water. ZooMed makes a nice water bowl (Hermit Crab Ramp Bowl) that is attractive and is good for hermit crabs due to the stepped edges for easy access in and out, and their Repti Rock dishes work well too. You should also place natural sea sponges in the water dishes; some crabs will press on these to get water to drink and they help regulate the humidity.
All water given to the hermit crabs or used in the tank should be dechlorinated (drops available at pet stores). Salt water should be prepared using a marine aquarium salt such as instant ocean (mix as for saltwater tanks), not the salt made for freshwater tanks and never table salt.
Online Retailers with Good Selection of Hermit Crab Supplies