If I treated the guppies in the tank with MelaFix and there are also fry in the tank, will the fry be okay, or will they die? I haven't had any experience with medicating fish, so I'm totally at a loss. How will the fry react?
I don't /think/ it will. I used it in a tank with very young pygmy cories in it and they were fine but I've never kept guppy fry so I can't say for sure.