Hello I have had my tank up and running for a few years and I have had an issue on and off for a year or so it seems. I followed all my fish through quarantine by using coppersafe at 2.5 for 30 days based on Hannah tester followed by Prizipro. Then they go into the main tank. Anyway issues come and go. The issues are head shaking, scratching, rapid breathing and darting across the tank. Nothing that is causing my fish to die (mostly) but it's very frusturating. I take the fish out and try copper again followed by prazipro. At times I use formuline. It works for a bit, but it appears to keep coming back. Any suggestion on what it is? I believe it is Flukes. Currently I am using hypo salinity and fresh water baths.