Safe Substrates for Hermit Crabs


by Simon Griffiths


Hermit Crabs are interesting creatures. The most common Hermit Crabs varieties available can live up to 30 years or more if properly cared for! Over the years, there is a lot of information about Hermit Crab needs, yet severe blunders in hermit crab habitat selection are still widespread.

The substrate determines whether or not the hermit crab can successfully molt and develop a new exoskeleton, as well as withstand attacks from cage mates during this critical period. Even if everything else is perfect, your Hermit Crab will die well before its “due date” if it doesn’t have access to the right substrates at the right depth.

This post covers safe substrates for hermit crabs


Safe Substrates for Hermit Crabs

Since hermit crabs are nocturnal, they dig in the substrate when hiding or molting. During the day, the crabs relax in the sand and scavenge for food at night when it’s dark. It is critical to have enough of a nice, healthy substrate in your tank because they lie on it all day. Sand, forest bedding, crushed coral, gravel, small river pebbles, potting soil, and wood chips are some of the most popular substrate options on the market.

However, keep in mind that not all of these kinds are suitable for crabs. Some of them make it difficult for hermit crabs to dig, while others are too rough and can’t keep moisture well. The different substrates are described below, along with which ones are suitable for pet hermit crabs. 

Related  What Do Hermit Crabs Need In Captivity Apart From The Tank?

What Safe Substrates are Available for Hermit Crabs?

1. Sand 

Sand is a good choice of substrate because it is appealing and crabs can tunnel under it without collapsing. It is fairly expensive, too. For “Hermit crab sand” you don’t have to buy in sacks. The hardware store’s 50-pound sandbag can be used as hermit crab sand.

Check always for any insects or cracks in your bag before you put any sand (or another substrate) in the crab. Sniff it, and don’t use it in the tank if there is a strange smell. Although most sand is washed or sterilized before it is packaged, rinsing the sand, letting it dry, and baking it in the oven is still a good idea.

The sand’s depth should at least be sufficient for crabs to dive into it. It should also be moist, so when you set the crab, add a little water, but not too watery; you should aim for “sandcastle consistency.”

2. Forest Bedding

Forest bedding is a very good medium for crab use as it is sold when compounded into a tough brick. The bedding of the forest consists of coconut fibers that almost seem like soil, so finely scattered. It hardens a little over time, allowing crabs to dig under it.

You need to place the bedding of the forest in a bowl, add some water and wait until it is softened by sufficient water for easy breakage. Then add pre-arranged salt water to make it healthier. The crabs like to eat the substratum, which gives them the additional nutrients they require. 

Forest bedding is a good substratum because it keeps the moisture at a good level and does not mist the tank. The only problem is that fungal gnats can be attracted. These are small black bugs that can place eggs in your tank and start breeding there!

3. Other Substrates 

Many crab owners opt for the sand and forest bedding combination, which not only makes the best substratum for crabs probably but also provides great digging consistency. The crushed coral is also a suitable substrate for hermit crabs; with many hermit crabs owners saying that their crabs love the crushed coral.

How You Should Set up the Substrate in the Hermit Crab’s Tank

Naturally, when it is time to molt, crabs dig underground for two reasons. First of all, they need the darkness that is buried to secrete the molting hormone (ecdysone). Secondly, they need the isolation and protection which is provided by being buried underground. A hermit crab that just dropped its exoskeleton cannot move until it gets hard and gets control of its muscle.

Related How Long Does It Take A Hermit Crab To Molt 

Typically, a moist, sandy/sandy mix is the best and safe substrate for hermit crabs. In order to simulate the substrate, use a moist mix of clean running sand and moist coconut fiber to cover the entire bottom of the tank. 

This helps with water retention. The aim is to create a deep moist substratum with minimal care while the hermit crabs are inhumed. Large hermit crabs can remain underground while they molt for months. So you won’t trouble them while they are most vulnerable. 

Related How To Tell Whether Your Hermit Crab is Molting or Dead

Humidity is crucial for hermit crabs to bury. You will want to maintain your substrate in a “sand -castle making consistency,” so that your crabs can dig and pack an underground cave and airspace to molt. The dry sand is going to cave in as they try to bury. Fill in the mixture with purified or even salt water to maintain packing consistency.

When crabs are buried, nebulize the surface so that the substratum does not dry until the crabs have reappeared from molting. When you are certain that no crabs are buried or molting, all you have to do is remove everything from the tank and add fresh water, to moisturize the substrate, and to remix it thoroughly so that it is ready for the next crab to melt.

Wrapping Up 

 For hermit crabs, sand is the substrate of choice as they like to burrow into it. Sand found freely on a playground or in home stores works well and is low cost, although aquarium sand is also fine. Crabs need room to mold and to grow (or to throw off their skin). The skin of your hermit crab does not grow and stretch out as it does with our skin, so it has to burrow very deep in the moist sand to melt. Your hermit crab’s body will stop the molting process until it is dead if there is inadequate space to molt.

Simon Griffiths

Hi guys, my name is Simon, a fellow pet lover. I love everything about traditional and exotic pets so I am here to help you create a better home for your pets.