I have a 55 gal tank with 4 fish, 2 damsels and 2 green chromis. Other than the fish, I've added 1 turbo Snail (large), 1 Emerald Crab, 1 Blue knuckle hermit, 3 peppermint shrimp and 4 scarlet hermits. There are several hitchhikers, including several small "gorilla" crabs, 3 urchins, numerous...