I have 4 fish in a QT tank right now: a pair of clownfish, a yellow clown goby, and a tailspot blenny. When I saw them all start to scratch themselves on the PVC in there, I started treatment with Coppersafe. It has now been a month, and yet I am still seeing a fair bit of scratching, and now both clownfish have a spattering of little white-ish dots on them, as well. The copper levels have remained in the theraputic range the entire time, so I don't understand what's going on here. I thought it was ich or maybe velvet, but if it were, that should be gone by now, right?