I have a 40 gallon tank with like 22 fish and I have 1 red tail shark. he always has his top fins down I tried using fluke treatment. He seemed to get better but then when he got better and I stopped dosing. like 2 weeks later he was doing the same thing. It seems that he has a little of fin rot also. He also itches on stuff. I heard also that him having his fins down could be stress. Can itching be stress also? Also is his tail color a good health indicator to determine if he is stressed. Also I have noticed that my mollies are getting fin rot also I am pretty sure that these are fin rot on the mollies. Maybe fin nipping I doubt it though. I also noticed one of my cherry barbs itching himself to so I wanted to know if it is most likely flukes or if it can be stress? How should I treat the fin rot? I know it could be stres rot also but I am not sure if it is treated the same? Thanks for the help!