Hey I;ve had the disease that you are talking about, and lemme guess the angels poop is funny coloured too. Now I can't remember the name of the disease, but I remember the chemicals that I used to treat it. THe stuff was a combination of metrodinazol and metheline blue. If they have the white fungus on them its from poor water quality. I would suggest at least a 30% water change. on the first day before you treat the tank. This is going to sound wierd too but there is a tea tree oil medication available in the better fish rooms that helps with destroy the fungus and bad bacteria and it doesn't kill the good stuff. Yes it totally works tried it and within days my little guys were noticibly better. After you treat the tank as directed on the bottle do another major water change. And every day for about a week after that change 10% which will completely freshen up your tank and remove most of the medication. If you don't do the water changes the medication can and will build up over time and you can risk losing all of your fish because the water has become toxic.