I had what may be a similar thing. I’ll post the advice I got from a longtime discus owner. I followed the advice, and I was able to save 9 of my 13 discus. I’ll post the conversation I had below:
“Hi Dale, thanks for the help with my discus. I’ve kept fish for a long time, but discus for almost a year. I don’t want to bother you, but I have a question about the discus plague treatment. if discus require such clean water as so many posts say, then how can I keep it clean without changing the water for 10-14 days? Just trying to understand the rationale, because I really want to succeed with keeping discus. Thanks again, George”
“hi George....what you are fighting is Columnarus . IT's life cycle is 14 days and thrives on fresh , clean O2 water. SO, when you do a change ( as you seen when it all started ) it blows up and will kill your fish. The more you try to do ( meds, etc ) the worse it gets. HONESTLY, listening to these idiots online does NOT help !!!! Any meds...will kill ( again, it stresses the fish ) We also could never figure out why column. meds didnt work, but it is assumed that it is viral based and the columnarus is a secondary result ( like aids, etc ) SO, after years and years of doing this and discussing it with hundreds of breeders....what i mentioned is the best . Temp up, lots of salt ( which helps the FISH , but doesnt help the column or cause it to bloom ), lower PH and most important...TIME !!!! We all have made the mistake of seeing the fish getting better after a week and thinking.,...."i can do a change now", BUT NO !!!!! Have to wait until the last fish comes out of it. Please also remember, your tank is "hot". If you add fish ( discus, angels ) they will get it....once you see the last fish, wait at least 3-4 weeks before adding new. also, good idea to have a tank in another part of the house for new arrivals. I HAVE seen this go airborne !!! Does that help ?? What have you done so far ?? Do you want me to call you and walk you through this ??”