Hello! My fish have black spots which I believe are flukes. I read that sometimes they go away on their own, but the spots have gotten worse gradually. The fish do not appear in distress, however I would like to keep the disease from spreading. About half of my tank is affected so I need to treat the whole tank, but my concern is that I have scaleless fish in the aquarium. What would be some safe medications to use with scaleless fish? I have tried prazipro with no luck.