If you’re looking for an entertaining pet that’s generally easy to take care of, you can’t do much better than a hermit crab.
With the right tank setup, these little crustaceans will thrive.
They’re social, active, and fun little creatures that are a joy to watch.
Here’s what you need to know about caring for a hermit crab.
Table of Contents
Choosing the Right Size of Hermit Crab Tank
A lot of people assume that the small containers the hermit crabs are sold in is a suitable home but that’s not actually the case. The truth is hermit crabs need a lot more room to move around.
A 10-gallon aquarium is the smallest size enclosure you should use. If you have 1 or 2 small hermit crabs, this is the ideal size.
If you have more than 2 or if your hermit crabs are particularly large, you should actually use an aquarium that’s at least 30 gallons.
Getting the right sized tank is really important. In addition to giving hermit crabs the room they need, it also prevents them from escaping. Your tank should have a lid.
If you live in a warm, humid environment, a mesh lid will work but if your home gets cold and dry, plexiglass is best.
Setting Up a Hermit Crab Tank
There’s a lot to consider when setting up a tank for your hermit crab.
In fact, it’s very important that the tank is set up before you bring your new pet home. That way, you can make sure everything is perfect before you put your hermit crab inside.
Here are the major things to consider when setting up a hermit crab tank.
Hermit Crab Temperature and Humidity
When you consider that a hermit crab’s natural environment is by the shore, it makes sense that temperature and humidity are so important.
Humidity levels are really important. Hermit crabs breathe through modified gills but they need moistened air so they don’t dry out. If their gills dry, the won’t be able to breathe.
Their tank should be tropical in nature with a relative humidity of 70% or an actual humidity of 50% or higher.
Because humidity is so important, it’s not enough to guess what it is. Your hermit crab’s life literally depends on it so it’s essential to have a hygrometer to keep a close watch on humidity levels.
Some easy ways to do this are to keep the substrate moist but not wet. If you set your tank up like a shoreline with the substrate sloping down, you can recreate their natural environment by leaving the elevated area dry and the lower area damp.
It’s also a good idea to mist the tank every day and make sure you have a plexiglass lid in place if you have a mesh lid and find that too much moisture is escaping.
Another thing you can do is add an aerator to their water bowl. This involves getting an air pump, tubing, and air stones that you would use for an aquarium to circulate the water in the bowl. A bonus is that this will also keep the water from being stagnant.
Temperature is important, too. Too high and they’ll suffer from heat damage, too low and their metabolism slows down which can cause irreversible damage.
If you live in a cooler environment, keep your hermit crab tank away from the window, especially in the winter. You’ll need to add heat lamps and/or tank heaters to maintain the proper temperature, which should be about 75 degrees F at all times.
As with humidity, guessing what the temperature is just isn’t enough. You’ll need an accurate thermometer for constant monitoring.
Hermit Crab Substrate
The best substrates for hermit crab tanks are either sand or coconut fiber. There are two reasons for this.
First, they’re easy for you to clean. Second, they’re similar to the natural environment of the crab so it allows them to dig, tunnel, and borrow.
As far as sand goes, you can use ordinary play sand or invest in special terrarium sand. Because coconut fibers are a little easy to tunnel through, some hermit crab owners us a mixture of both.
Be sure you avoid substrates that don’t allow them to dig, like wood chips or gravel.
Hermit Crab Decor, Plants, Hiding Places
Hermit crabs are active little creatures that love to climb, burrow, and hide.
By providing them with the right kind of decor, you can create an environment for them that’s close to their natural one which will keep them happy and help them avoid boredom.
You should always have extra shells in the tank for the crab to use when it’s ready to change habitats.
These shells should be the same size as or a little bigger than the one it’s currently using. About 3 different shells per crab is ideal.
Here are some of the things you can safely add to a hermit crab tank:
- Twigs and branches
- Ceramic pots or figurines
- Fake plants
- Wooden or plastic shelters
Hermit Crab Water
Hermit crabs require access to both freshwater and saltwater. Provide your hermit crab a bowl of each, making sure it’s large enough for each crab in the tank to submerge itself and easily accessible.
This means that if you have a very large crab and some smaller ones, the bowl should be big enough to accommodate the largest one. If the smaller crabs have a hard time getting out, put some sea sponge or shell in the water to give them something to use as a bridge if needed.
For freshwater, make sure it’s dechlorinated. The chlorine in tap water is harmful to hermit crabs so use dechlorinating drops if you plan to use tap water. You can also use bottled water, too, but that can get expensive over time.
As for saltwater, use the same type of water that you would put in a tropical aquarium. You can purchase aquarium salt at the pet store and add it to freshwater to make it but, whatever you do, do not use table salt. Table salt contains iodine which is harmful to hermit crabs.
Hermit crabs use this water for a few reasons. They use the freshwater to drink and alternate between saltwater and fresh for their shell depending on their needs. Shell water is used to hydrate their gills and they control the salinity by switching between fresh and saltwater.
One more thing, hermit crabs are extremely sensitive to metal so all water bowls should be plastic or ceramic.
Hermit Crab Lighting
Lights can be really beneficial to a hermit crab tank. First of all, they’re an easy way to help you maintain and temperature but the can also lower humidity so it can at times be a delicate balance.
The best way to use lights in a tank is to recreate a day and night cycle that’s similar to what your hermit crab would experience in nature.
You can use fluorescent bulbs that give off UVA and IVB light to create sunshine and use the time to cycle the light appropriately.
Hermit Crab Feeding Basics
The best way to understand what to feed a hermit crab is to consider what they eat in the wild. Hermit crabs have access to a variety of food, including fruit, leaves, plants, grasses, and anything washed ashore. They’re not picky and will eat just about anything.
Does that mean you can feed them just about anything?
No! While the exact nutritional requirements of a hermit crab aren’t known, we do know some of the things they need. For example, they thrive on a diet that’s rich in calcium, carotene, and antioxidants.
Feeding your hermit crab a diet that’s rich in fresh fruits and vegetables, meat, nuts, seeds, and fish. Unprocessed foods are essential and you can even add some oak leaves or tree bark.
If you provide your hermit crab a well-rounded diet, you probably won’t need to use commercial crab food.
Hermit Crab Tank Mates
The best tank mate for a hermit crab is another hermit crab or several hermit crabs. They’re social creatures and live in large groups in the wild.
In fact, when it comes to adding more hermit crabs, the more, the merrier, as long as they can fit comfortably in the tank.
Other than more hermit crabs, there aren’t too many things you can add to their environment. Other crabs, like fiddler crabs, are too aggressive to be kept with hermit crabs when they’re molting. As for snails, it’s likely hermit crabs will attack them.
Isopods are one option. Isopods are crustaceans that can get pretty large in the wild but small varieties can work well with hermit crabs.
Hermit crabs are great pets that thrive in the right tank set up. They’re social animals that live in large groups in the wild so it’s best for them to live in pairs if not larger groups in an aquarium.
While hermit crab care isn’t overly complicated, they are a little more difficult than their reputation makes them out to be.
Follow the information in this guide for how to establish a safe and happy home for your new pets and you’ll soon see why hermit crabs are such an interesting addition to your family.