Some background … I have a Blonde Naso and a Kole Yellow Eye Tang in my 20 gal quarantine since 6/28/19 … Also in the quarantine is Springeri Damsel that came out of my DT about 5 weeks ago because he was getting beat up by one of his buddies … but he looks fine now. The problem… the Kole tang has been rubbing on the PVC fitting I have in the tank. This has been going on for the last couple of weeks. Both are very timid and hide behind the sponge filter as soon as I get close but are otherwise very active. Both are voracious feeders and consume the Sea Veggies and spirulina I put in the tank twice a day. I can see nothing on either fish or the damsel. Otherwise all are active and seem happy. So the question is should I treat them with copper or something else? I was hoping to get them into the DT on 7/27/19 because I don’t see anything on them.