I have a 30 gal tall with 2 lg erectus ladies, 1 med erectus male, 3 med tigertail males (1 pregnant), and 1 med tigertail female. Multiple zoas, colt corals, mushrooms, leather mushroom, feather dusters, firefish goby, 2 yellow watchman gobies, nassarius snails, hermit crabs, live rock, live sand, fake plants, protein skimmer, Ehiem filter, Aquaclear filter, phosphate reactor and water pumps to move water in the lower half.