I got this Flagfin last weekend. It was eating pellets and looked healthy. As you can see, there is something going on up it's side. This just showed up over night. It was barely visible prior. It is not swimming around and is just lying on its side up against the rock I have in QT. Any suggestions?

New angels & butterflies are notorious for getting these "red streak" infections. When that pops up, this is the best medication to use:

