Setup Instructions for a Sand Tank for a Pet Hermit Crab

A close-up of a hermit crab

Hermit crabs don't require a fancy housing, but the right humidity and temperature are essential for their wellbeing. Because they evolved in warm, tropical regions, land hermit crabs require a warm, humid habitat to live.

Picking the Tank

Either a glass or plastic aquarium will be comfortable for hermit crabs. Pick a lidded 10-gallon aquarium. A sliding glass door will be effective in keeping humidity in check. Although these plastic cages make wonderful temporary houses or isolation tanks, the little plastic homes with accessories supplied as hermit crab kits are too small. Hermits are really highly gregarious creatures and are best maintained in groups despite their moniker.

The Substrate

Sand is the preferred substrate for hermit crabs because it allows them to dig deep. Aquarium sand is also OK, but playground sand, which is available at home improvement stores, works well and is less expensive. The sand can be sterilized by rinsing, drying, and baking it (at 300 degrees Fahrenheit), after which it can be cleaned and used once again. Calcium-based sands are lovely and available in a variety of hues, but they are costly.

Other choices include fiber bedding especially for reptiles, including the Forest Bedding made from coconut fiber. Since the fiber is very finely crushed and resembles earth, it is suitable for digging. Although Forest Bedding or sand are also good options, your hermit crabs could prefer these surfaces for molting. Crushed coral is another option. Use of wood shavings or gravel should be avoided.

Maintaining Proper Temperature

At temperatures between 72 and 80 degrees Fahrenheit, hermit crabs thrive (22 to 27 degrees Celsius). The crabs are prone to grow weakened, stressed out, and unwell if the temperature routinely falls below 72 degrees Fahrenheit. To maintain the crab tank at ideal temperatures, you will need to use a heater at least some of the time, unless you live in a tropical area. To maintain the proper temperatures, undertank heaters (UTHs), lights, or a mix of both might be utilized.

To give a warm side and a colder side, the UTHs can be positioned beneath one end of the tank. These will bring the temperature up a few degrees from the ambient level. These may be used in conjunction with a thermostat to maintain a particular temperature or you can set them on a timer to turn on and off to maintain temperatures for the best temperature management. Purchase a reliable thermometer for the tank and keep an eye on the area near the substrate for temperature changes. If the heater isn't heating the tank sufficiently, consider removing part of the substrates that are covering it; the warmer tank will result from the thinner substrate. You can deepen the substrate if the tank is becoming too warm. To get ideal, consistent temperatures, some experimenting might be required. To provide the crabs a variety of temperatures, make sure the tank has a temperature gradient.

Lights of various types can also provide heat for the tank; some experimentation with lighting may also be necessary to find the combination of lights and UTH that works best for your tank.


Hermit crabs were once supposed to be nocturnal, and it was assumed that lighting may stress the crabs out. However, low-wattage and specialized night light bulbs are an excellent alternative, and many crab owners have discovered that when illumination was added to the tank, their crabs became more active and would even bask close to the lights. A light-dark cycle should be present, ideally with 12 hours of light and 12 hours of darkness. This implies that fluorescent or day-glow lights should only be turned off at night, while special night-light bulbs can be used if preferred. It is not advised to heat the tank with a desk light or high-wattage reptile bulbs since they might cause the tank to overheat and become overly dry.

Using a reptile heating/lighting canopy over the tank is the simplest way to add lights. There are hoods with two ceramic incandescent bulb sockets; one may hold a day glow bulb while the other holds a night glow bulb. With a 10-gallon tank in particular, it is preferable to start with 15-watt bulbs and go up to greater wattages only if necessary. If it gets too hot, wood slats can be added to elevate the hood a little over the glass. Some hoods feature a third socket for a fluorescent light, and some owners say the Reptisun 2.0 fluorescent produces good results. Reptile heat hoods work best on tanks with glass tops or screens, however humidity control is more difficult with a screen top since the lights will be quite hot and could melt the plastic. The tank may be heated using both lights and undertank heat.


Hermit crabs require a tank with enough humidity in addition to the right temperature. Because crabs "breathe" through their gills, the humidity of the air affects how well the crabs exchange oxygen. The crabs will practically die if the air in the aquarium is too dry. They require relative humidity levels of between 70% to 80%. It is worthwhile to spend money on a hygrometer, also known as a humidity meter, which you can get in the pet store's reptile area because this is so crucial to the crabs. Additionally, excessive humidity is undesirable since it will lead to condensation and promote the development of germs and fungus in the tank.

If the tank is encased with solid sides and top, the water dish you give in the tank should be plenty for producing the desired humidity. Try putting a sizable chunk of a natural sea sponge in a water dish if you need to raise the humidity level (remember to always use dechlorinated water). The sponge has many surfaces for evaporation and may store a lot of water, which will increase the humidity. Keep a few sponges on hand so that you can switch them out and clean them periodically (soak them in extremely hot dechlorinated water or a sea salt/water mixture, then let them dry fully since they are an ideal environment for bacterial development). The lid can be adjusted by covering the majority of the top with plastic wrap or transparent packing tape if a mesh or vented lid is making humidity management difficult.

Cage Furnishings 

There are three necessities for furnishing the cage: stuff to climb on, a water bowl, and a food dish.

  • Climbing: 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. Artificial plants are also a great addition to the crab tank. Periodically change things around or add different items to provide some variety and interest for the crabs. Some enterprising individuals even use Legos to build climbing structures for their crabs.
  • Water: Hermit crabs should have access to both fresh and saltwater, so 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 saltwater 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. 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 (the drops available at pet stores). Saltwater should be prepared using a marine aquarium salt such as an instant ocean (mix as for saltwater tanks), not the salt made for freshwater tanks and never table salt.
  • 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 for .
  • What paint can I use in a hermit crab habitat?

    The best paint to use around hermit crabs is acrylic paint, just make sure to keep it away from the inside of their shells.

  • What kind of rocks should I put in a hermit crab habitat?

    After using a good layer of sand as substrate, small river pebbles are great for hermit crabs.

  • What can live in the same habitat as a hermit crab?

    Hermit crabs can co-exist with dozen of reef-dwelling fish species, and they can also live with other hermit crabs.

  • Why does my hermit crab habitat smell?

    A variety of causes, including garbage, rotting food, and irregular cleanings (which leave molted exoskeletons lying around), can make your hermit crab's house smell bad. When agitated, hermit crabs also exude hormones that have an unpleasant scent. This might happen when their habitat is dirty, when they are handled excessively, or when they are alone.