I've been reading about how tangs need all of this room, but I have a 55 gallon, with 25 lbs. of live rock. In the tank, I have 15 fish including a 5 inch Naso Tang, 3 small Yellow Tangs, a Blue Hippo Tang, a small Percula Clown, a large Clarkii Clown, 5 Green Chromis, 2 Yellow Tail Damsels...