Copper is safe to use with Prazi-Pro, a wormer that should solve the poop problem. Hikari, mfg of PP, says that the PP is less effective when used with other meds. Fish should be kept in the QT for a couple of weeks after ich treatment anyhow and that's plenty of time to do the two doses of PP. PP is very safe and can even be used in reef tanks; IMO, all fish should be treated with PP. Ideally in QT when they are first acclimating.