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Setting up a proper crabitat

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 petstore 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 30 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. A MINIMUM of 2 gallons of space per small or medium hermit crab but 5 gallons per crab is much more humane. Large and jumbo crabs will need much more space, 10 gallon minimum. A 10 gallon tank is too small for even one large or jumbo crab. 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. Over head lights or heat emitters are not recommended for inexperienced pet owners. They make it challenging to maintain the correct environment in the tank.

Ways to heat your crabitat

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. Not all moss is safe so be sure to check our list: Which types of moss are safe for my hermit crabs?

Substrates for hermit crabs

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.

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:

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Hermit Crab Vacation Care

Coenobita eyes Credit - Sean Carroll

Hermit crab vacation care ideas Coenobita eyes Credit – Sean Carroll

There may come times when a crabber finds they must leave their hermies for a few days, or wish to go on vacation and are concerned about their hermies being cared for.

To go for a week end, most can ensure with reptile reservoirs the hermit crabs will have the water they need as well as food if a little extra is added to the food dish. Make sure the foods that are left will not spoil/mold in a couple of days.

For peace of mind regarding the temperature of ones crabitat one may wish to invest in a Thermostat for the heating source.

With a controlled crabitat temperature, most times it is easier to regulate the humidity percentage within the tank as well.
Below please find postings from some of the Crab Street Journals members as to what they had done prior to leaving for a few days or before going on vacation:

grant wrote:

I’ve seen these before at PetSmart and a couple other pet stores and would not buy them myself.
HBH Hermit Crab Vacation Food Blocks

I wasn’t too crazy about the ingredients and yes they do contain ethoxyquin which is known to delay molt.


  • Keep all materials organized and labeled
  • Have dedicated measuring tools handy
  • Do a thorough cleaning before you leave

Use the same dish for each type
For example:

  • blue dish – salt water
  • orange dish – fresh water
  • Show helper how to mix a batch of each
  • Ask helper to clean and replace daily


  • Keep fresh in air tight containers
  • Ask helper to clean and replace daily
  • Do not over feed
  • Barnicle clusters make great additions because they look nice, the crabs can climb on them and the crabs can eat them.
  • Other foods need to be removed to avoid mold and spoiling.


    • Make sure gauge reads accurately and is easy to see
    • Inform the helper of what range it should read in
    • and how to make adjustments if found out of that range.

Other thoughts…

        • Have extra dishes so they can be rotated. (no need to rush the cleaning and drying process)
        • Introduce the helper to this forum!

Daethian wrote:

I divvy up foods into small daily portions in shells or dishes, then cover with saran wrap and place in the fridge so they just open and pop it in the tank. I normally alternate wet with dry foods so they can leave the dry foods in for two days. With the food portioned out and ready to go it’s very easy.

I mix my water a gallon at a time so there is no need for them to mix any of it. I mark the milk jugs accordingly of course.

I always keep dried leaves and flowers strewn in my tank to ensure there is always something to nibble on.

You can do the same with ground egg shells and cuttlebone.

You can make one of my Oreo Vacation Cookies and leave it in the tank. It will keep at least a week. Beyond that it gets a little moldy if there is any left over. I have been feeding more than needed while testing. One cookie would last most people a week with little left over.

Lette wrote:

I’d like to make up several servings of food a day so she wouldn’t have to worry about what to feed them. I was thinking of using a large pillbox. the type that has the days listed on them. It might help w/proportions of dry food & that way I know they are getting a variety of dry good food. Lette

Misscranky1 wrote:

Here’s what I have been doing for quite a while now when I get ready to leave.
I buy fruits and veggies and save the clippings in a ziploc bag in the refrigerator with a paper towel in it. This keeps the moisture down. I also buy a bag of mixed berries in the frozen food section because they’re just fruit and they’re easy to use.
I also buy organic baby food and a little goes a long way.

On the day before I leave, I chop my fruit and veggie clippings, I get out two ice trays and sprinkle a little big of chopped pieces into each compartment. I will even put a piece of a sardine in a few of the compartments too. I then spoon (about a 1/2 teaspoon) the baby food into alternating compartments and I mix it up so there’s not the same thing in all of them. I put a few pieces of the mixed berries on top of each compartment then sprinkle some eggshells on top of that. It actually looks very pretty by then.
I freeze the food and once they’re frozen, I pop them out into an airtight container and keep it in the freezer. Labeled of course.

I also mix up some dry food mix which is some fruit and flower mix, brown rice, grits, dried apples, maybe even their cherrished cheerios and put that in a jar with an air tight lid.

I buy 2 gallons of distilled water and add ocean salt to one of them.

When I get ready to leave, the instructions are to change out the water every other day, put a cube of food one day, then change it out with dry stuff which is ok to be there for 2 days. Alternating if they want to.
I do the same with the humidity gauge and point it out and label the flap of plastic on the lid which says… if humidity is above 80, open the flap. If it’s below 70, close the flap.
Not too bad.

It usually works out really well and I don’t have them worry with the light because the tank is near a window. It gets natural light.
I haven’t had a problem.

It’s nice because if the friend puts the food dish where I put it, the cube of food thaws nicely over the undertank heater in a short time.
I forgot to add that I put some meat.. like shrimp or bloodworms in there too.

Ladybug15057 wrote:

A couple years ago when our whole family went to Georgia for a weeks vacation I knew our ‘sitter’ would only be stopping in once a day, mostly towards evening. Even with the large water ponds, I wanted to make sure the hermies had water 24/7. So I had bought reptile reservoirs for all the tanks. To make sure the little ones could get access to the reservoirs (just in case) I cut small strips of Velcro and stuck them along different parts of the outside of the reservoir water end. I used a sharpie permanent marker and marked each reservoir ‘tube’ either ocean or fresh water. (as well as the underside of the reservoir) This made it a little easier for our ‘sitter’ and the reservoirs I suggested to only change the water out every 3-4 days or so. (unless they started to look nasty, but to change the ponds water at least every 2 days)

To make sure the little hermies could get out of the reservoir pond, I placed a few marbles within each one. I used votive candle holders filled with water and marbles in the middle of where the UTH was located to help regulate the humidity within the tank. Having the Electronic temp controllers to regulate the heat output of the UTH gave me peace of mind that the temperature within the tank would be fine.

Freeze dried or dehydrated foods were prepared prior to our leaving, as well as the fresh foods. Dry foods were prepared in dishes and covered and then placed in the refrigerator to keep them fresher longer. (These were to be changed every 2 days) For the fresh foods that were prepared I used the daily pill dispensers that were to be emptied into the cleaned dishes. The fresh foods were to be changed daily. There are some Kaytee healthy food toppings for birds as well as some Hakari foods one can use.

I too left directions on the top of the tanks about the humidity readings, as well as what that tank was called. (we have a few tanks and they do have names: Jumbo tank, Strawberry tank, my main tank, etc.) The food dishes we prepared on the plastic wrap were marked accordingly too with masking tape on top.

In case a hermie had molted, I already had critter keepers set up within the main iso tank. All they needed was water added to the water dishes. I had left instructions on top of the tank lid as to which water went into which colored dish. I had also prepared a couple smaller dishes clearly marked for the iso tank in case there was a molter while we were away.

Hermit wrote:
Great ideas, everyone! I do the premixed and frozen foods for my crabs too.
When I am going away for awhile, I put a pot of “living” food in the tank. I have these small plastic toy buckets that I fill with worm castings, and I sprout seeds like millet, beans, spinach, etc. in them on a sunny windowsill. Then, when I am going to leave, I put the pot into the tank. The hermies can eat the sprouts, dig up any unsprouted seeds and eat those, and even eat the worm castings.
I do this for them even when I’m home, but it’s especially important when I’m away.