Hello Everyone. Just wanted to get your opinion on this. This Potter Angel is in my QT. He is eating like a champ. I got him from Marine Collectors where they QT their fish with copper before shipping. I take the extra precautious not adding my fish straight to the DT when shipped by Marine Collectors- rather watch them for 2 more weeks. My QT has no medication at the moment. All parameters are great and stable. Potter has a worm like on his left fin. Not sure if his fin is swollen or he does have something. Don’t want to nuke the guy with medication if I cannot identify what it is. Can someone help me identify what’s on his fin? Thank you.