So, back in the hobby after several years. First new fish, a Flame Angel, is starting to not look so good, I’ve had the fish in QT for about 3 weeks. Has been eating and looked good. But today I’m noticing one fin not moving much. I took him out for a closer look. I don’t see much, but there is the beginning of maybe some whitish haze near the mouth. Also, seems maybe paler overall. Maybe Velvet? What is the best treatment considering angels are sensitive to copper? Thanks.