My dang grouper is rubbing himself all over the rock and bottom of the tank. while I dont see any spots he is going crazy. I had a power brown tank that got ich and died(he stopped eating). The grouper on the other hand still eats like a horse. This is my 180 gallon mostly fish only. I have a couple turbo snails and a little GSP and some colt that I can take out and move. My question is how to treat it? Dose it with medicine or leave it alone? All my water paramaters check out good except its time for a water change and my nitrates are just barely starting to show.