Three days ago I noticed my GFO had moved up to the top of the media reactor and dumped the brown "dust" in the rank. My filter socks were dark brown. I cleaned the filters and added a poly filter. The next day my flame angel came down with Popeye in both eyes and can't see out if either. Today my emperor angel has Popeye in one eye. Water perimeters in range, nitrates <10. I thought Popeye would heal on its own with good water quality. Now I'm not do sure. Setting up a hospital tank tonight and will move them tomorrow. Wondering what the best treatment is.