Let’s look at how to set up a proper hermit crab habitat, which we refer to as a crabitat.
Basing your tank set up on what you saw at the pet store or mall cart where you may have purchased your hermit crabs is a recipe for disaster. Kritter Keepers and wire cages are death boxes and should never be used.
Listed below are the primary components of a proper set up and we will discuss them in detail. If you are not willing to equip the tank properly you should return your hermit crabs or rehome them, they will not thrive without a properly set up habitat. Captive hermit crabs can live over 40 years in the proper habitat. Most hermit crabs die either in the first month of ownership, during the first molt of ownership or within the first year to 18 months. So yes, they can technically ‘survive’ in poor conditions but why on earth would you purposely do this to an animal???
A simple list of the items you will need to properly outfit the crabitat. There are low cost options for most of these items.
- Tank
- Lid
- Light*
- Heat
- Substrate
- Gauges
- Bowls
- Climbers
- Hiders
- Plants and Vines
The tank itself should be glass or lexan and large enough to comfortably house your hermit crabs. Small crabs can be happy in a smaller habitat while jumbo crabs need a minimum of 15 gallons per crab. More than 10G/crab is always better! A hermit crab must live many decades to reach jumbo size.
Plan for the future when purchasing your tank, allow for the growth of your crabs or additions to the herd. A used tank is perfectly fine and will greatly reduce the cost of supplies.
The tank must have a lid that retains humidity. A screen lid with glass, lexan or plastic wrap on top is what is typically used. Hermit crabs require humidity to breathe. Opening the lid for feedings and water changes each day usually provides enough air exchange. Fresh air flow reduces mold, mildew and fungus growth.
Light is required, whether they are used as your heat source or not. Hermit crabs require a normal 12 hour cycle of light and dark, it is vital to the molt process. If your crabitat is in a well light room that will meet the need of daytime light. Do NOT place your tank in directly sunlight!
UVB is believed to extend the life span of captive hermit crabs. UVB bulbs must be mounted in such a way that there is no glass or plastic barrier between the bulb and the hermit crabs. Most people mount the lid inside the tank. Bulbs must be replaced every 12 months.
For nighttime viewing, LED in red or blue is safe. Your hermit crabs do not require a light at night.
Hermit crabs require warm temperatures. This can come from overhead lights or from heat pad (often called under the tank heater or UTH) which is placed on the wall of the tank and not under it, above the substrate line. Over head lights or heat emitters are not recommended for inexperienced hermit crab owners. They make it challenging to maintain the correct environment in the tank.
Global Temperature and Precipitation Maps by Month
Gauges are the only way to monitor and maintain proper heat and humidity levels. The tank temperatures should be a range of 75F to 82F. 72F is the absolute minimum and your tank should not remain at this temperature long term. A temporary dip or spike in temperature is not cause for concern. A range means that your tank should have areas of different temperatures. Some species seem to enjoy slightly warmer temperatures but the common clypeatus is happy in the 75-82F range. Check the substrate temperature as well to make sure it is not too hot. Overly warm substrate will kill molters or discourage molting. Humidity ranges should be 70-80% this is relative humidity. Occasional higher humidity is not cause for concern but maintaining excessively high humidity could lead to flooding or lethal bacteria due to over saturation of your substrate. Your analog hygrometer will need to be calibrated before use. Wireless, digital gauges are relatively cheap and are more accurate than analog gauges.
Substrate should be a mix of 5 parts play sand and 1 part eco earth. The ideal mix will keep the sand moist throughout. The consistency should be so that you could easily make a sand castle. That means that molting burrows will not collapse from drying out. We suggest using a brackish water to expand the eco earth bricks. This will help reduce the chance of mold. The eco earth should be DRY when mixed into the sand so you don’t end up with water logged substrate at the beginning. You can always add water once the crabitat environment is stable, if needed. In many cases it is not needed. Starting with too wet substrate will lead to flooding and/or bacterial blooms. Mix your substrate dry, close up the tank with the lid and all the decor and allow it to stabilize for 48 hours. If the humidity is too low you can mist the substrate. Then wait another 24 hours and check the humidity again. It is much easier to add moisture to the substrate than it is to dry it out once it is in the tank.
The eco earth will help maintain humidity but you may need to add some moss pits if your levels are too low. Most moss is safe- we have not found any that are unsafe for hermit crabs.
Thanks to Savannah Claussen for this handy chart!
Three bowls will be needed. Two of the bowls should be deep enough to allow your hermit crabs to submerge themselves. One should be fresh water and one should be ocean water made with marine grade salt mix. All water that comes in contact with your hermit crabs must be treated to remove chlorine, chloramines, ammonia as well as other chemicals. The third bowl will be for food. These don’t have to be reptile dishes specifically but they should be something that your smallest crabs can easily enter and exit. Many people use disposable Gladware type bowls for water pools. We recommend placing a rock, fake plant or coral in the pool for the smaller crabs to climb out.
Take a deep dive into hermit crab pools.
Places to hide, things to climb on, as well as plants and vines are important to create an environment that is stimulating and enriching for your hermit crabs. Huts do not have to be made of coconut shells, many things will work. The same holds true for things to climb on. There are lots of DIY ideas or less expensive ideas for creating vertical climbing opportunities. Fake plants and vines from a craft store will work as well as the ones you find at the pet store. Some live plants are safe for the crabitat but your hermit crabs will most likely kill them.
Creating additional levels in your crabitat to maximize usable space
Your goal should be to create an environment that is as close to what hermit crabs experience in nature as possible. Hermit crabs live primarily on beaches, so think tropical!
Here are some examples of properly set up crabitats:
