How to Raise Saltwater Hermit Crabs

By Sandra Ketcham

hermit crab image by alwayspp from

Saltwater hermit crabs are active, social and intelligent critters. They're fairly easy pets to care for once their tank is properly set up. Have a tank prepared before bringing home your new pet. If you can't -- say you've carried a marine hermit crab home from the beach -- make sure you get him into an appropriate environment right away; saltwater hermit crabs need saltwater to survive.

Step 1

Fill your aquarium with saltwater that contains no trace of chlorine, which is deadly to marine hermit crabs. The tank's pH should fall between 8.0 and 8.4, and nitrite and ammonia levels should be undetectable. Aim for a specific gravity of 1.021 to 1.028 and nitrate levels of less than 10 ppm. Keep kH levels at 143 to 215 ppm.

Step 2

Keep more than one crab so yours does not become lonely. Hermit crabs are social creatures, even though their name implies otherwise. For maximum health and happiness, have at least two marine hermit crabs of the same type in your tank at all times.

Step 3

Determine the ideal water temperature for your crabs by finding out what part of the world they originate from and mimicking those conditions in your tank. Your pet store may be able to help if you cannot figure it out on your own.

Step 4

Give your hermit crab several inches of sand to dig and hide in. Add some live rock and some places for your crab to climb.

Step 5

Feed your saltwater crabs appropriately, based on size. Smaller crabs can get by on a diet of algae, plants and uneaten fish food, while larger hermies need crab pellets, lettuce, dried seaweed, poultry pieces or other food. To ensure each of your crabs gets enough to eat, offer each one a piece of food with tweezers or tongs.

Step 6

Provide your hermit crabs a variety of shells so they can switch when desired. Some crabs will use the same shell until they outgrow it; others like to change shells daily.

Step 7

Monitor the gravity and temperature of your tank regularly to keep your hermit crabs healthy and happy. Hydrometers, thermometers and saltwater testing kits are available in most pet stores.

Step 8

Handle your crabs under the water. Unlike land crabs, saltwater hermit crabs are marine animals that need to be submerged. If your crabs are coastal crabs, though, they may tolerate being out of the water for short periods.

Items you will need

  • Hydrometer
  • Thermometers
  • Sand
  • Live rock
  • Crab pellets


  • If your crabs frequently try to escape, they may need access to land for climbing. Arrange your tank so they have a land area to climb on.

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