Hey everyone, I have had this yellow tang for a few years and moved him over to a newer tank setup a few months ago. Since then his dorsal fin has become worn down and I cant figure out why. I feed him mysis shrimp, green seaweed, and flakes so I dont think its his diet. It it possible my rockwork is too low and his fin is being worn down by rubbing against the rock? Also hes in the tank alone so there aren't any other fish doing it. Thank you for your help!