My Tuscano tetra began to have what I thought to be a fungal infection, I treated with marcyn, but only had three doses (I have since ordered more) And today I noticed a white lump on my oto cat whom I have had for years, and has been very healthy. I’m thinking about treating the whole tank with Maracyn. Thoughts or comments? These fish are not new nor have I introduced any new fish, so it seem to come out of the blue, water parameters are good. I did remove some apistos fry recently to sell, but that all.