So I've slowly been losing fish. It first started with Camallanus nematodes that we treated with Levamisole. We've since added some new fish, despite quarantining are now having problems. The first fish to get sick and die was one of my Dwarf Gouramis. He was always weaker than the other one, never really thrived and one day he had Dropsy so we culled him. I lost a Platy, but I think she was killed by the Serpae Tetras (I only had 5 at the time and they were aggressive, I know have 10). I've noticed the platys just not looking as healthy and robust as they should. No real symptoms other than being slightly more reclusive. They have had stringy white almost clear poops. I thought worms so I treated them with PraziPro. That didn't do anything. Since I had added new fish and didn't treat them for Camallanus in QT I went ahead and treated the main tank to be safe. I do think we had some Camallanus because some fish improved, but not everyone. I just lost another Platy mysteriously tonight. He has been reclusive, clamped fins, but no other symptoms... coming out to eat. Well suddenly tonight he too had dropsy, red gills and a red spot the size of his gill between his eyes onto of his head... not hole in the head, looked nothing like any case of hole in the head I've seen. We culled him too sicne he had Dropsy and I've never had any luck treating Dropsy. We have high pH from out water, somewhere above 7.6, probably around 8, but the tank has always had high pH and not seemed to be a problem. As of 4 days ago the ammonia was 0, tonight it was 0.25 ppm. No other fish are showing signs of ammonia poisoning at this time so I think there is something else going through the tank. Other symptoms are occasional flashing on objects... like only a few times a day, and one platy goes up to the other fish and shimmys. Not sure how else to describe it. Two of the older more established platys just kind of hang out around the driftwood with loosely clamped fins. I still have stringy white poop from just about all the Platys (I have yet to see a tetra poop) and the only thing left that I know of that can cause it are flagellates. I'm not really sure what to do other than a water change. My tank has live plants too, which limits what medications I can use. Any help in trying to figure out what is going on would be appreciated.