A few days ago I noticed one of my cpd's was swimming oddly. Upon further inspection I noticed her tail was clamped. At the time I really didn't think much of it, but I just fed them and found 2 more with the same issue. I also found another that had a white patch on her tail as well. I've had all the fish in the is tank for 3 months now and have added nothing new since then and all the parameters check out okay. I'm not sure what the deal is and how to treat it as it is obviously spreading. Any ideas or suggestions.