I put a new kole tang in my tank. He is medium size maybe 3 inches. He seemed to be doing well for the first few days but today and tonight he seemed to not be doing so well. He's the largest fish in the tank with 2 clowns, cleaner wrasse and 5 chromis. I checked all my levels and its 0 ammonia, 0 nitrite, 0 nitrate and .25 phosphate, 8.2 PH. The only other thing that I feel may be contributing could be that I just finished my ich-attack treatment in the tank, but all the other fish including invertebrates seem to be doing well and the tang hasn't shown any signs of ich. There is plenty of live rock with plenty of places for him to hide and he's barely been out at all. That is a 75g tank. The the rock work is centered so there is lots of swimming room front and back. So he shouldn't be stressed due space with his current size. Any thoughts or advice?... I know he will outgrow the tank but my 125 is wrapping up a cycle before I plan on transferring healthy fish. Essentially 75 will be my quarantine tank once the 125 finishes.