In my 125g, I have about 30 platies and my only adult male is looking like he has parasites. What do you guys think? I'm going to move him to an empty tank and treat him with him with api general cure which is all I have right now. I don't know what could cause this other than the fact that I incorrectly dosed my ferts and ended up with 80ppm nitrates (Nitrates lowered now). Could this be what caused the disease? I've dealt with this same disease before and it has never ended well. I also would like to know if I need to treat the other fish and not just the infected one. And if I do need to, what is the best way to treat such a big tank?