My tank is a 90 gallon with about 100 lbs of fiji live rock. My blue hippo is about 4 to 4 1/2 inches. Also in this tank is a lawnmower blenny, a strawberry psuedo, a yellow tang about 3 inches, a pair of clowns, and of course my new pearlscale butterfly which is also about 4 inches. Also there is a cleaner crew of snails and crabs. All in all a very happy and healthy tank.
thanks again for the help
Jeff