Just giving a little update. Today is day 4 of treatment, and everyone seems to be doing pretty good. I have one angel that looks a little stressed but not too bad. The Corys are still very active, and eating well. The white patches are still present, but do no seem to be getting worse. I tested my water today, and it looks like I have 0.25 - 0.5 ppm of ammonia. I dosed with Fritz Complete, and will do a water change as scheduled tomorrow.