We have a 3 1/2 " blood parrot that developed a severe case of fin rot. in a matter of days he was practically "finless" with just a stump of a tail. He was lethargic, trying to swim occasionally, but with practically no fins, was unable to do not much more than wiggle about. It spent much time upside down, or floating on it's side, eating very little. We put it in an isolation tank and added 1 tsp. kosher salt/gal. and added Melafix daily, dropped the temp to 75 degrees. It didn't seem to be improving, maybe even getting worse, so we tried Maracyn tablets . We gradually decreased the salt content (water changes), but still added the Melafix daily, and still didn't see much improvement after half the Marcyn regimin. As a last ditch effort to avoid euthanasia, we decided to try peroxide on the little fella. We took him out and held him in a wet paper towel, applied peroxide with a q-tip to all the rotted fin stumps, and put him back in his tank. We finished the Marcyn regimin and continued the Melafix thru the whole ordeal . Within a week or so he started showing signs of improvement. He still was swimming upside down a lot, but that gradually improved. I only used one regimen of Maracyn, but continued with water changes weekly and Melafix daily. I stopped the Melafix after about 30 days. Today ( 2 months later) he is doing fine, healthy appetite, swimming upright, with close to 1/2" of new tail and fin growth. Hope this helps someone else.........