Setting up a hermit crab tank is more involved than what you see at most pet stores. The mall carts or souvenir shops where hermit crabs are housed are nothing more than a death-row prison cell for these little pets.
They need much more than a tiny metal cage or a plastic critter keeper. In fact, the metal mesh most hermit crabs are kept in is fatal to them.
You didn’t purchase these little hermits to watch them slowly deteriorate, so let’s see how you should really set up your crabitat.
Think Tropical Thoughts
In nature, hermit crabs live in a tropical paradise. When you picture that, what do you see?
I see soft, sandy beaches, smell the refreshing salty air, feel the warm humidity caressing my face, and see a lot of tropical trees. Of course, you can’t have a tropical paradise without salt water.
This is basically how you want to set up your hermit crab digs. You need a thick, soft, sandy substrate, heat, plenty of humidity, places to climb, areas to hide, saltwater, and freshwater.
As you can see, it’s probably a very stark contrast to what you saw when you got your little pet. Oh, yeah, those cute painted shells…they’re a big problem too.
Hermit crabs are tiny, so things that can be toxic affect them even more. The paint on the shells can and will eventually flake off. The hermit crabs—being scavengers—see the colorful pieces on the ground and think they’re something tasty.
Next thing you know, you have a sick (or worse) hermit crab. For the safety of the hermit crab, only use unpainted, natural shells for your little pet.
With the proper care, your hermit crab could live for 10, 20, maybe even 30 years and beyond. In the metal cages or tiny plastic huts, you might keep it alive for a few months, or maybe a year if you’re lucky.
A Basic List Of Necessary Supplies
There are tons of extras you can purchase for your hermit crab, but the following is a list of basic necessities for the long health of your hermit crab.
- Minimum 10-gallon aquarium tank
- A sturdy lid
- Light source
- A heating pad or lamp
- Temperature and humidity gauges
- Sandy substrate
- Places to hide
- Climbing logs or vines
- Three bowls–two for water, one for feeding
- Plants, you can use live or artificial
- Extra shells
- Hermit crab food
Right off the bat all of these supplies can add up. If you’re on a budget, you can often find second-hand items or cheaper alternatives with little time to search for them. I don’t know how many times I’ve found aquariums for sale super cheap at discounts or thrift stores.
Just be sure to clean and sanitize anything you purchase that’s been used before. Don’t use harsh chemicals like bleach though. A 50/50 solution of white distilled vinegar and water is sufficient to clean and disinfect without leaving behind a strong residue.
Now we’ll go over each of these supplies in detail to help you set up the perfect hermit crab paradise.
Get The Right Size Tank
Most hermit crabs won’t get larger than a few inches, but there are a few species that can grow rather large. The Ecuadorian hermit crab will only grow about an inch long at full size, while the Caribbean hermit crab can grow to the size of a baseball, or 6 inches long!
Hermit crabs are social animals, so you may decide to get two or three. Then again, you may start off with one just to see if it will be a good fit for you. Keep in mind though, how big your hermit crab will get in the end.
You don’t want to get a small, 10-gallon tank for three or four Caribbean hermit crabs, they will end up getting crowded and becoming aggressive toward each other.
The minimum size is 10 gallons for one small hermit crab. If that sounds excessive, think about their habitat in the wild. They have plenty of space to roam, explore, climb, and search for food. Try to give them plenty of room to stretch their legs.
If you’re getting a few hermit crabs to add at least 5 gallons per extra hermit, though 10 for each would be ideal. So for 3 hermit crabs, you need a 20 to 30-gallon tank. (10 for the first hermit, 5 to 10 for each additional. 10+5+5=20 or 10+10+10=30).
The Tank Must Be Able To Hold Weight
A quick word on the type of tank you’ll need. First, stay away from metal. Copper, chromium, stainless steel, lead, and other heavy metals are toxic to hermit crabs.
The wire mesh they are usually housed in before they are sold is made from steel, stainless, galvanized, copper, or other metals.
Next, you want to make sure you get a tank that will hold all the substrate you’ll need. Regular reptile terrariums aren’t typically built to withstand so much weight, so you need to look for tempered aquarium glass, Lexan, or acrylic. All of these materials are tough and made to hold the weight of water.
Here is a good quality 10-gallon starter tank. Aqueon Standard Glass Rectangle Aquarium
Hermit Crabs Need Lids
These little crabs are excellent climbers and accomplished escape artists. Small hermit crabs can even climb up the thin beads of silicone that hold aquariums together.
Once you have your crabitat completely set up, you’ll have climbing vines and wood which they need for exploration and enrichment. So if you don’t have a good, sturdy lid over the tank, you may find your little “Mr. Krabs” crawling across the carpet or hiding under the bookcase.
A sturdy mesh lid works fine, but if you want to keep more moisture inside, a slotted acrylic or glass lid works wonders.
Hermit crabs need a humid environment, but they also need air exchange to reduce the possibility of mold and mildew growth in the tank.
Add Some Tropical Light
Hermit crabs tend to be nocturnal, so you may find that your pet is much more active during the night, but they still need a light source. A 12-hour cycle of light and dark is essential during molting, helps their circadian rhythm and UVB rays help them absorb calcium and vitamin D.
You may be tempted to put your tank directly under a sunny window. This isn’t a good idea though. While typically natural sunlight is best, unfortunately, when the sun shines through windows and their aquarium, the heat can get concentrated.
The light is brighter and hotter. Putting your hermit crab’s enclosure directly in front of a window could be like putting it in a slow cooker oven.
The best thing to do for light is to purchase a tank light and a proper UVB bulb. If you’re using a glass or acrylic lid, you’ll need to mount the light inside the tank because the glass or plastic may filter the UVB rays out.
UVB bulb rays eventually fade, so they need to be replaced approximately every year.
Fluker’s Repta-Clamp Lamp with Dimmable Switch along with the TEKIZOO UVA UVB Light Bulb will supply your hermit crab with plenty of tropical light. Make sure you give them 12 hours of light, followed by 12 hours of darkness.
Add In A Heat Source
Since they come from tropical environments, hermit crabs like it warm. The best way to achieve this is to use under-the-tank heating pads, often shortened to UTH.
While they are designed to go under the tank, for a hermit crab set up they should be placed on the side of the tank, not under. We’ll get to the substrate soon, but with the amount hermit crabs need, a heater set under the tank wouldn’t keep the crabitat warm enough.
The ideal temp range for hermit crabs is between 75-85 degrees Fahrenheit (23-29 Celsius) during the day and 65-75 degrees Fahrenheit (18-24 Celsius) at night.
This adjustable heating pad will help you get the right daytime and nighttime temperatures for your hermit crabs, Tikaton Reptile Heat Pad.
Use Quality Gauges To Monitor Heat And Humidity
You’ll need to closely monitor the heat and humidity levels of your crabitat. Hermit crabs have gills they breathe through instead of lungs. For proper respiration, they need a humid environment, or their gills don’t work.
You can find cheap, analog temp and humidity gauges, but they need to be calibrated on occasion. They’re great in a pinch, and if you’re on a budget they can get you started, but digital is the best way to go. They’re more accurate and don’t need calibration.
Hermit crabs need to stay in an environment that maintains a 70 to 80% humidity level. To properly monitor these conditions, try out this REPTI ZOO Reptile Terrarium Thermometer Hygrometer Digital Display.
What’s A Tropical Paradise Without Sand?
Now let’s get into the all-important substrate. This is important because hermit crabs like to burrow and they need to molt as they grow.
Molting is the process in which crabs outgrow their shell and shed it. When they go through this process they come out soft and very vulnerable. It takes time for the new shell to harden.
When hermit crabs go through the molting process they like to burrow into the sand for protection. After they shed their outer shell, they then consume it for nutrients while waiting for the new shell to harden.
You’ll need a mixture of all-purpose sand and soil mixed together and 3 to 5 times as deep as the hermit crab is long.
All-purpose sand is found in most hardware or home improvement stores. It’s better than play sand because it holds moisture better, and some play sand is treated with antibacterial solutions that could be harmful to your hermit crab.
You’ll want to mix 5 parts sand, with 1 part soil. You can use coconut coir, eco earth, or potting mix. Just make sure if you’re using potting soil that it’s organic and contains NO FERTILIZER.
Once you have your substrate mixed you need to add some moisture to make it “clumpable.” Have you ever made a sand castle? That’s the consistency you want. It needs to hold together and not crumble or cave in when your hermit crab starts to burrow.
Whatever you do please stay away from calcium sand. This stuff is sold in pet stores and claims to be great for reptiles, hermit crabs, etc, but it’s trash! I may be a bit biased but this stuff is no good.
It doesn’t hold moisture well, in fact, it hardens when it gets wet, and it can stick to your hermit crab after it molts. Then the sand clings to it when it goes back to the shell.
Imagine having pebbles stuck in your shoes while walking for miles. That’s what that calcium sand does to hermit crabs.
I hate that stuff because when I first got my bearded dragons, I thought it was a great “natural” substrate for them. That’s what the package says! Well, after the calcium sand made both of them impacted, my vet told me that stuff is bad for all reptiles.
After a very expensive vet bill and a scare that I had inadvertently harmed my little pets, I stay away from that stuff like the plague.
Hermits Gonna Hermit
Next, you need a hermit home for each of the little critters you have. They can be coconut halves or elaborate hideaways but they need a place to hide away when they’re tired.
They need their light, but sometimes they just need to get out of the sun for a little while.
Hermits Love To Climb
Many hermit crabs live among mangrove trees and will climb the roots for shelter, protection from predators, or to hide away. For maximum enrichment and to satisfy the need to climb, be sure to add in some limbs, climbing vines, nets, or similar.
Cholla wood is an excellent option. There are also plenty of bendable, repositionable climbing vines you can purchase such as EONMIR 8-Foot Vines, and Flexible Jungle Climber.
Get The Proper Bowls
These bowls are vitally important for your hermit crab. They can’t be made of metal, but porcelain, resin, plastic, or glass is fine. You need one for food and two for water.
The water bowls need to be deep enough that your hermit can fully submerge itself, and be able to easily climb in and out. They do have gills, but these gills aren’t made for breathing underwater, so if they can’t get out of the water they can drown.
There are some bowls that have steps on the sides for hermit crabs to climb in and out, but you can also do this with small rocks.
You need two separate water bowls because hermit crabs require saltwater and freshwater. Be sure you never use tap water, it contains chlorine, and often metals that may not be bad for us but are way too dangerous for hermit crabs.
Use filtered, bottled water, or distilled water for your hermit crabs, and replace it daily so the water doesn’t get stale or stagnant. When mixing the salt for the saltwater bowl, make sure you use marine, aquarium salt and not table salt.
Hermit crabs need fresh water to drink, and they need salt water to help keep them moisturized and to help keep their shells on. Hermit crabs will keep water inside their shells.
This helps keep their gill moistened and creates a suction on their shells so they don’t easily fall off.
This two-pack of water bowls provides a perfect habitat for small hermit crabs. Zoo Med 2 Pack of Hermit Crab Ramp Bowls. They have ramps on both sides, allowing the hermit crab to easily climb in and out.
Add Some Green To The Crabitat
To really make your hermit’s home pop with color, add some plants. Plants can offer shade when they need it, places to hide out, things to climb on, and even fresh air if you plan on growing living plants.
While live plants can make the crabitat look extraordinary, if you’re just not that great with plants, or don’t want to spend the extra time on live plants, artificial plants work wonders.
You don’t have to trim them, you don’t have to replant artificial plants or worry if they’re getting enough fertilizer. Another thing you don’t have to worry about with artificials is if the plant is toxic to hermit crabs.
These shelled little ones are omnivores and some will munch on live plants. If you’re going with live plants, you need to make sure they aren’t toxic to hermit crabs.
A few live plants you can add to your hermit crab tank if you choose, include:
- Air plants
- Spider plants
- Loose leaf lettuce
- Aloe plants
Finish It Off With Some Shells
As you may know already, hermit crabs have soft abdomens and don’t grow their own shells. As they get bigger they will change their shell to better accommodate them.
Sometimes they just don’t like their old shell and want something different. Always keep some extra shells in various sizes for all of your hermit crabs. When shells are scarce, hermit crabs may fight for shells.
Larger hermit crabs can and will pull smaller crabs out of their shells if there aren’t enough around them.
Just leave an assortment of unpainted, clean shells along the bottom of the tank. When your hermit grows or wants to change they will go around and try different ones out until they find the perfect fit.
What To Feed Your Hermits
Now you have your tank all set up! That’s it, right? Now you can let your little crabby do all the crabby things they do, but wait, what happens when hunger strikes? What are you going to feed your hermit?
You could feed them commercial hermit crab food, but these don’t really meet the needs of hermit crabs. Plus, hermit crabs in the wild enjoy a wide variety of different foods and will quickly get bored with the same old pellets.
Pellet food is fine on occasion, but they need fresh vegetables, protein, and the occasional fruit. They also need calcium. This can be provided in the form of calcium powder, or cuttlebones. You can also feed them crushed eggshells.
Some vegetables you can feed your hermit crab include kale and other dark, leafy greens, (no iceberg lettuce, it’s basically green, crunchy water), broccoli, carrots, green beans, and peppers.
You can also feed them nuts, seeds (most of them love chia seeds), and whole, bulk grains.
Some fruits you can feed hermit crabs include bananas, strawberries, and melons. Just don’t feed them fruit every day, the excess sugar isn’t good for them, but it’s great as an occasional treat.
Hermit crabs also need sources of protein. This includes fish (sardines, tuna, mackerel, catfish, salmon, etc), shrimp, insects, bloodworms, eggs, chicken, and beef. You can feed them raw sources of protein or cooked. Just don’t add any seasoning such as salt.
A quick word on insects. Crickets and mealworms may be too fast for hermit crabs to catch, and they can bite your hermit crab. To prevent any harm to your hermit, it’s a good idea to squish the insect head before offering it to your hermit crabs.
Keep in mind also that hermit crabs are tiny and only eat a tiny amount at a time. If your hermit crab eats everything you put in the bowl, add a little more, and if they leave excessive amounts, scale back how much you feed them.
Remove any uneaten food after 24 hours to prevent rotted food, bacteria, and mold.
What’s the best way to heat a hermit crab tank?
A: You can use a heat lamp or a UTH pad. A heat lamp is recommended for experienced owners because it may take some time and adjustments to get the right temperatures. A UTH pad needs to be set on the side of a hermit crab tank so the heat will get inside.
Do hermit crabs like sand or rocks?
A: Sand is a better substrate for hermit crabs. They usually live on sandy beaches, in mangrove forests, or on the rich, soft ground of forest floors. Hermit crabs also like to burrow, so sand works much better for this need. You can put a few rocks in the crabitat for your hermits to climb on, but rocks are not recommended for a substrate.
Do hermit crabs need a sponge to drink?
A: Some hermit crabs may like to drink from a sponge, but these things can be more hassle than they’re worth. They are expensive, they get ripped to shreds by hermit crabs, and they can harbor bacteria. You’ll also have to mist or water the sponges several times a day because they will dry out quickly.
Do you want to pay $4 to $8 a week for a sponge, or spend that same amount of money once for a good water dish that won’t get torn up?
Compared to the tank your hermit crab was in when you bought it, the proper setup is like the Ritz-Carlton. The tiny, metal mesh tanks you usually find hermit crabs in are a horrible representation of what they need.
When putting hermit crabs in little metal, or tiny plastic habitats, they won’t last long. But when you create the right environment for your hermit crabs, they will live for decades. These cute little creatures deserve to be taken care of, so take the time and give them a good Crabitat.