Get an appropriately sized aquarium
You need to give your hermit crab a nice home to live in, and getting a suitably sized aquarium should be your first priority. In case you own a single hermit crab, a 10-gallon aquarium is perfect. Keep in mind that hermit crabs like company, so you should adopt two to three hermit crabs at a time.
Line the aquarium's floor with sand
Get hermit crab-friendly sand from your local pet or hardware store and line it in the bottom of the aquarium. You are required to fill up to two to three inches of sand. You can even use normal playground sand if you can't find the specialized variety.
Keep a wet area in the aquarium
You are required to keep a wet area, or make a pool for the hermit crab in one corner of the aquarium. This will not only keep it moist but will also provide it with calcium. Your hermit crab will also be able to drink from the pool in order to stay hydrated.
Use a small natural sponge
In order to help in evaporation, you need to get a small natural sponge around the size of your fist. Place the sponge in the water and the air in the aquarium will become humid, which is preferred by your crab.
Provide hermit crab food
Get special hermit crab food from your local pet store and feed it to your crab once a day. You can also feed fruit, vegetables or cereals which have essential nutrients for your crab.
Place different spiral shells
You need to give your crab room to grow. Place different spiral shells in the aquarium but make sure they are bigger than the crab’s own shell. When it outgrows its current shell, it can then easily choose a new home.