How to Build Hermit Crab Pools

Written by Shadoe Haffner, AKA GodzillaHermitCrab on deviantart, AKA wolfnipplechips on hermitcrabassociation


  • 2 mini paint trays from Walmart (need one for fresh water, one for salt) ~$6
  • aquarium silicone from a pet or fish store MUST BE AQUARIUM SILICONE $6-9
  • some pebbles (can be found at craft stores or walmart) $0-3
  • a knife or sharp object $0-10
  • something to smear the silicon (a rice spoon works great) $0-3
  • well-ventilated area $0
  • scissors $0-5


  • air pumps $12
  • air stones $1-2
  • aquarium tubing $2-4

Step 1: Make sure you have all your materials

Step 2: Using the scissors, cut off the back part of the paint trays to go from this:

To this:

Step 3: Use the knife or sharp object to scratch up the ramp surface. This will help the silicone stick for much longer. Make it as rough as you can.

Step 4: Use the rice spoon to smear a thin layer of silicone on the ramp.

Step 5: Sprinkle the rocks on, and press them down.

Step 6: Add some more silicone and smear it around until you get a mixed layer of rocks/silicone on the ramp. Try to make it even, but it’s ok to be messy.

Step 7: Wait 48 hours for the silicone to dry. Before adding to your tank, be sure to smell the silicone. If it still smells like silicone, keep drying it. Only add it when there is no more smell.

Step 8: (Optional) Set up you pump, tubes, and air stones to make a bubbler pool. This will boost the humidity in your tank, create a flow of fresh air, and keep your water fresh and oxygenated a bit longer.

Good luck!

A pic of these pools in action without the air stones.

I like these pools because they are simple to make, deep enough for large crabs, safe for tiny crabs, and compact so they take up very little space.

Eventually, because silicone does not bond very well to plastics, you will have to re-do the silicone/rocks after 1-2 years if you treat the pools well. It’s crucial that you do step 3 with ferocity. If you ignore step 3, you will have problems after about a month.