I have been having some trouble with my discus so had to dose the tank with myxazin. Beforehand i tried looking up on the internet what was toxic to BGK but couldn't find much and it didn't say anything on the bottle(don't use with BGK eg). But today i have noticed his bottom fin is going pale, as well as a little of his body. I have quickly put him in a seperate tank with fresh RO water and am planning on doing a water change tomorrow. He is a good 10" or so and i would hate to loose him. Is there anything anyone can suggest?