Ive done what my local pro's tell me, and done lot's of research from turning the UV off carbon filter out, regular gravel clean's, water changes, medication, salt etc. it will go away than three days it will be back, this has been going on for one month now and it's really annoying is it because the gravel collect all the waste etc.? i have tried sand substrate but it's a b to clean and take lot's of care i go to school full time and work full time as well i can tend the take everyday but i need more than petco/petsmart worker's to guide me through this hard time, i love my fish in there and so does my son but if it's going to wipe of half my fish everytime i get ick there's no point in keeping it