Hermit Crab Sand & Substrate

Hermit crabs need to be able to fully bury themselves in your aquarium substrate to protect themselves during molting—the time when they shed their exoskeleton and move into a larger shell. Add enough aquarium sand to your tank or terrarium so that your largest hermit crab can fully bury themselves. Hermit crabs range in size between 1- to 4-inches.

Hermit crabs require a fine sand-like or soil-like substrate at the bottom of their tank so they can easily bury themselves when they are ready to molt. The most popular aquarium substrate for a hermit crab habitat is sand. Other substrate options include finely ground fiber crushed coral. Avoid gravel or wood shavings, as these do not work well as hermit crab bedding.

If you aren’t sure that you’ve chosen the right terrarium sand, observe your hermit crabs. If you notice them digging themselves into the sand, then you’ve picked a good aquarium sand substrate.

Hermit crabs are happy with wet or dry hermit crab sand as long as their habitats contain the right amount of humidity. Hermit crabs do best when the humidity in their habitats is between 70% and 80%. In fact, hermit crabs possess gills and require a certain amount of humidity in order to breathe properly. A high amount of humidity will help keep the sand substrate from drying out completely. You can help keep the humidity at the right level with reptile water accessories in your habitat.

Ideally, you’ll want to invest in aquarium sand substrate or another substrate formulated for hermit crabs and other pets. You’ll find these solutions at Petco. Buying your aquarium sand at Petco will ensure the sand is safe and free of potential toxins. You can always choose to buy regular sand at a big box hardware store. In this case, however, it’s a good idea to thoroughly wash the sand and then bake it at a heat of 300 degrees Fahrenheit to sterilize your substrate and make sure it is safe for your pets.