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How To Care For A Hermit Crab: Tank, Care & Feeding

Lindsey Stanton Profile Picture

By Lindsey Stanton

hermit crabs out of their shells, hermit crabs closeup

Hermit crabs, just like any other pet, especially aquatic ones, need to be taken care of properly. These are pets, so obviously you want to keep them happy, healthy, and alive. There is not all that much work involved in terms of taking care of a hermit crab, but there are a few things that you need to know and need to get right if you want a thriving hermit crab habitat, this post covers how to care for a hermit crab the right way.

Setting Up The Hermit Crab’s Tank – Living Conditions

The first thing that you need to do before you go out and buy yourself any number of hermit crabs is to set up their home, much like you would do with fish, birds, or any other pet for that matter. Let’s go over how to set up the new home for the hermit crabs you are going to get.

white spotted hermit crab in shell walking along sand in tank aquarium
Image credit: Zuzha, Shutterstock

The 8 Things You Need For Hermit Crabs Are:

1. The Tank

The first thing that you need to do before you get any number of hermit crabs is to get the tank to house them in. Keep in mind, you will probably want to go for a glass tank because they are very clear, look the best, and are quite strong too. You can however go with an acrylic tank if you choose. In terms of the size of the tank you get, it should be around 20 gallons in size for every 4 hermit crabs that you have.

A general fish tank or reptile terrarium is the best way to go here. Remember that every 4 hermit crabs need at least 20 gallons of tank space. Moreover, keep in mind that hermit crabs should have at least 2 other crabs with them for company and should never be kept alone. This means that you are looking at a 20 gallon tank.

2. The Humidity

One of the first things that you should buy before purchasing your new hermit crabs is a hygrometer, which is a device that measures the humidity in the air. You see, hermit crabs breathe through hardened gills, which means that while they can breathe oxygen from the air, it needs to be really humid as the gills were designed to function in wet or at least very humid environments. The humidity in your crab tank needs to be between 75% and 85%.

If the humidity in the tank is any lower than 70%, you hermit crabs will die a very slow and extremely painful death due to suffocation. They need humid air in order for their gills to be able to absorb oxygen from it. Things like little ponds, natural moss, and sponges filled with water can all help to keep humidity levels in your hermit crab tank ideal for the survival of your hermit crabs. On a side note, moss is actually a good addition not only because it helps maintain humidity, but because hermit crabs like to eat it too.

hermit crab
Image credit: Pixabay

3. The Temperature

Another important thing to get right in your hermit crabs’ habitat is the temperature. These are tropical animals and by no means do they do well in cold conditions. Ideally, the tank for your hermit crabs should always be between 75 and 85 degrees Fahrenheit.

You are most likely going to need a heater specially designed for hermit crabs, one that will heat the tank from the bottom up and can be attached to the back of the tank. This will also help ensure that the humidity levels will stay within the proper range. If the temperature in the tank is too low, it can cause irreversible damage to your hermit crabs.

Being too cold will cause your hermit crabs’ metabolisms to slow down to the point where they won’t really eat anymore, thus causing them to die of malnourishment. They will also become slow and sluggish, have compromised immune systems, and be highly susceptible to a wide range of diseases, many of which can be fatal. You definitely need to buy a thermometer so you can keep a close eye on how warm your hermit crab tank is.

4. The Substrate

In case you are not sure, the substrate is the layer of material which goes on the bottom of the hermit crab tank. There is really only one type of substrate which is ideal for hermit crabs and that is sugar sized arrogate sand. Anything bigger or smaller than sugar sized sand may injure the crab or inhibit its mobility. Also, playground sand for sandboxes may contain harmful additives which can poison your hermit crabs, so definitely do not use that.

You are going to want to use de-chlorinated salt water to wet the sand until it is about the consistency you would need to build sand castles out of. Crabs like the sand to be wet just like in their natural habitat, plus the wet sand will help to maintain humidity levels too. You do not want to use aquarium gravel for substrate because crabs like to dig and will not be able to dig and make caves in aquarium gravel.

You should also not use calcium sand for the substrate because it clumps up and can smell pretty bad too. Remember that hermit crabs like to build caves, dig, make little passageways, and hide under the sand, plus they like to molt under the surface of the sand as well. The sand you get needs to be able to support these caves and tunnels without caving in on the hermit crabs. The substrate should always be at least 4 times as deep as the height of your biggest crab, so that they can dig and make tunnels without reaching the bottom of the tank.

Next, you need to keep the substrate fairly clean. Dirty sand can cause mold to grow, which can be harmful and even deadly to hermit crabs. You should change the sand in your hermit crab tank at least once every six months. Moreover, you should do a monthly check to see if there is mold growing in the sand or if there is some kind of ant, mite, or other insect infestation occurring. If you see any insects or mold you need to change the substrate immediately.

A good way to prevent mold and decay from occurring is to engage in regular spot cleaning, which means cleaning up crab waste whenever you see it, and also cleaning up uneaten foods. Keep in mind, never change or clean the sand when your crab is molting (changing its exoskeleton) because it can disturb the natural molting process and even kill the hermit crab.

To keep the substrate clean and to sanitize it, you can always bake the sand in a 250 degree oven for 2 hours to kill of any germs or mold. You can also clean any shells and dishes in your hermit crab tank by boiling them in de-chlorinated salt water every few weeks. This will prevent mold and other contaminants from growing and spreading.

hermit crab on sand
Image credit: Pixabay

5. Climbing Items

Hermit crabs are natural climbers. They like to climb up rocks when it is low tide to look for food, and they often like to climb up wood too. They do this to search for food and for fun too. Something you can get is a little Choya log or stump to give your hermit crab something to climb on. Lego, hemp nets, untreated natural wood, and rough rocks can all help achieve this for your hermit crab tank.

Keep in mind that you should never put anything in your hermit crab tank which has been painted because paint can be lethal to hermit crabs if ingested. Also avoid anything that has been treated with harsh chemicals because they can be fatal to the hermit crabs as well. Natural rocks, clam shells, other marine animal shells, some plastic toys, and natural woods all make for great climbing surfaces.

6. Hiding Places

Hermit crabs can get stressed out, they like to hide from the sunlight, from people, and they just like their privacy. This is true for most animals. They also like a place to feel secure when they feel scared, which is why you need to provide them with some kind of hiding place. Something like half a coconut shell, a rock cave from a pet store, broken pots, and anything else that can serve as a cave or hiding space will do. Just make sure that the opening is big enough to easily fit the hermit crabs, that they can turn around in it without getting stuck, and make sure the edges will not cut or hurt the hermit crabs.

7. Live Plants

Hermit crabs are going to love having some live plants around. Whether be it hide under or around, to mock its natural habitat, or to give it some food to snack on, a hermit crab is going to appreciate a few live plants. The best options to go with include real bamboo, Venus fly traps, and spider plants. You do need to be aware of the fact that your hermit crabs will most likely snack on the plants, so don’t expect them to get very big or last very long.

hermit crab
Image Credit: JetKat, Shutterstock

8. Water

You definitely need to provide your hermit crabs with access to water. To be clear, in order for hermit crabs to stay hydrated, to breathe, and to balance the salinity in their shells, they need to have access to both fresh water and salt water. There is no getting around this because it is absolutely necessary for their survival. You can use some sloped dishes to do this, or you can also dig little ponds in the substrate (lined with a water retaining material) in order to achieve this same effect.

You need to have one pond or dish with salt water and another with fresh water. Make sure that the water dish or pond is deep enough so that the hermit crabs can get water in their shells. Also make sure that it is a sloped are so that the hermit crab can still get out once it is done in the water. Yes, hermit crabs can drown so this is important to keep in mind. Line the slope with some rough rocks so the hermit crabs can easily climb out.

It is a good idea to have an area that is sloped, with a deep end and a shallow end. Make sure to buy special hermit crab slat to make the salt water and never used salt intended for spicing up human foods. Whatever you do, make sure that all water does not contain chlorine. If you are going to be using tap water, make sure that you use a de-chlorinating agent to remove all chlorine. Chlorine can be very deadly to hermit crabs.

How To Care For A Hermit Crab

Ok, now that you have the tank set up properly with everything you need to keep your hermit crabs happy and healthy, you need to know how to take care of them. Here are some of the most important care tips for you to know.

1. The Type Of Hermit Crab

There are various types of hermit crabs out there (this post covers the common types and sizes), most of which can be found in pet stores. The most common hermit crabs to be found in pet stores are wild purple pinchers, often known as Caribbean Hermit Crabs. Just know what type of hermit crab you are buying.

2. Be Careful – Acclimatization

You need to be careful with hermit crabs as they are fairly fragile and can scare easily. Once you bring your new hermit crabs home, simply let them be in their tank for a few days without disturbing them. This will let them get accustomed to their surroundings. Hermit crabs go through a period of de-stressing, where they get acclimatized to their new home.

During this period, which can take just a few days or even several months you should change their food and water, but otherwise let them be. Once you notice that they don’t hunch or recede into their shells when you pass by them you can begin to insert your hand into the tank, let the hermit crabs explore your hand, and eventually even pick them up and hold them in your hands. This is very important to keep in mind because hermit crabs can die after you buy them simply from being too stressed out.

3. Molting & Shells

Your hermit crab is going to dig under the sand and build itself a cave. Don’t freak out if you don’t see your hermit crabs for a couple of weeks because they are probably just molting. Don’t bother your hermit crabs when you know that they are molting, because they need to molt in order to get a new exoskeleton and to survive. The stress from disturbing your hermit crab during molting could very well kill it.

When your hermit crab molts, because it is growing and needs a new shell, don’t take the molted shell away. The hermit crab will eat the old molted shell for nutrients in order to strengthen its new shell. On that same note, your hermit crabs are not in the wild, which means that you need to provide them with the new shells that they are going to live in. Always keep many hermit crab shells in the tank which are the same size as their current shell, and some that are slightly bigger.

Always get natural shells that have not been treated with any chemicals and have not been painted as those can be poisonous to your hermit crab. Keep in mind, Caribbean hermit crabs prefer circular openings, while other species like Ecuadorian hermit crabs prefer oval shaped openings.

hermit crab
Image Credit: Note Studio, Shutterstock

4. Feeding

Of course, just like any other pet you have, hermit crabs need to be fed and they need to be fed the right foods. Hermit crabs are scavengers by nature and will eat mostly anything from plants, fruits, and veggies, little insects, small live foods, and even rotting meat too. Keep in mind that you should never buy commercial foods with fillers or unwanted compounds, and you should never feed them anything hot, spicy, or anything with preservatives in it. Those things can make your hermit crab sick and may kill it.

Hermit Crab Feeding Schedule

Some things that you can feed your hermit crabs include silver sides, fresh shrimp, freeze-dried krill, blood worms, and small chunks of other seafood such as clams, mussels, oysters, scallops, and other small pieces of seafood. You can also feed them un-marinated and non-spiced pieces of beef or chicken, which you can grill lightly or feed to them raw. If you have a lot of crabs you can even give them a fish head every now and then (preferably not in their living tank as this will make a stinky mess).

Hermit crabs also love to eat plants, fruits, and veggies, so those are always good options too. Make sure to change their food every day and look for buried food. They like to bury their food which can cause mold and decay, which once again can be dangerous for your hermit crabs. Some things that you can feed your hermit crabs include fresh pineapple, apples, pears, guavas, watermelon, cantaloupe, papaya, mango, bananas, strawberries, coconut shavings, egg shells, hard boiled eggs, peanut butter on whole wheat toast, and even plain popcorn. Keep in mind that you should never feed your hermit crabs anything in the Allium species of plants such as garlic or onions.

5. Other Tips: What Do Hermit Crabs Like To Play With?

Hermit crabs do like to play so give them a bit of attention. You can carefully take them out of the tank and let them wander around. They love to walk across your shirt, your hands, and over various surfaces. They do need their humidity to stay alive, so never take them out for more than 15 or 20 minutes because they will begin to suffocate. Also, never let your hermit crab drop or fall under any circumstance because a 3-foot drop is more than enough to kill them. Always make sure to give your hermit crab a good surface to stand on, because if they feel as though they will fall, they will pinch.

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As you can see, besides setting up the tank properly, there is really not that much work involved when it comes to taking care of a hermit crab. Just follow all of our tips and directions and you will undoubtedly have a thriving hermit crab habitat in your home.

Featured Image Credit: Kurit afshen, Shutterstock

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