I had a disease outbreak. Needless to say I lost all but one sailfin. She went through full quarantine per your instructions. Copper with Hanna Checker. All meds were removed two weeks ago. Today she looks like this...
Is her Sailfin completely gone or am I just seeing things? Also, did you transfer into a new, sterile QT (at least 10 feet away) after 2 weeks worth of copper treatment? What Cu level did you treat at??
So, after seeing the new pics I'm pretty confident that those are viral lesions. I see this on tangs a lot post copper treatment. Basically, she has a virus living inside her body, copper suppresses the fish's natural immune system, so she has an "outbreak" (think human herpes virus).
Best thing to do is get her into clean water (no meds), and start soaking her food in vitamins (Selcon, Zoecon, Vita-chem). Also, feed nori daily. Basically, you are trying to boost the immune system to send the virus back into remission. There is no "cure" for fish viruses. Symptoms can only be managed.
I’m back! She got better... but not fully recovered... she now looks like this... tomorrow is the day she can go back into the main tank. I don’t want to introduce something to the tank. But if stress related it will prob help.
It will. Also, remove any carbon if you are running any. Carbon removes a lot of organics and nutrients from the water that will help the fish recover from HLLE. They are things we cannot identify, catalog, test for....but there is more than enough anecdotal evidence to correlate HLLE with excessive carbon usage.
Soaking the foods in vitamins should help the fish fully recover.