How many hermit crabs per tank should i have?
a 20 gallon tank is a bit crowded with 8 hermit crabs. If you want to get more consider upgrading to a larger set up. usually it’s 1-2 gallons or more per tiny crab 2-3 gallons or more per small crab 3-5 gallons or more per large crab. if you have too many in a small space they will become more aggressive towards one another. They really should have lots of space to roam around and moult.
