I have a sunburst platy with clamped fins. She's been this way for about a week. I moved her to a hospital tank. Water is fine. No ammonia, no nitrites, nitrates 10-20ppm. All of the other fish in the community tank she came from seem fine. I thought it was some type of fungus and used anti fungal meds. A week later and she seems to be getting worse. No other visible signs of anything wrong. Any ideas?