Need advice on this one. My only Serprae Tetra from planted tank was scratching sometimes after fertilizers or water change so I believed it was the conditioner or ferts irritating the fish. In the early days the fish swam around more & was not picky about food & looked good. However the fish began to hang in the back more & not come out as much + it would make sudden quick flicks to the side like something was attacking it. I decided to treat with prazi thinking skin or gill flukes. So I medicated with prazi for a week 2 doses with what seemed to be some relief from the symptoms. But they come back & I read about the flashlight trick to find velvet & I believe I saw what looked liked golden scales or sheen on the gill area. I removed the fish to hospital tank treated with copper safe , now on day 5 the sheen is still on the fish. I keep the tank at 82 degrees. I am now second guessing my diagnoses. I use prime as a water conditioner + follow dry ferts regulations. Still not sure if the bright gold looking skin or scales are his natural color or velvet. The fish was NOT QT before entering the tank. I will never do that again. Any advice on the diagnose?