First, make sure his environment is proper for him. He needs a tank between 2 and 5 gallons in size, and his water should be clean, and heated to between 76 and 84 degrees. He prefers to be very warm. Second, the tail looking awful does not mean that he still has the disease, it may mean he just needs to grow his tail back, and that will take time. You can speed that along by doing small, frequent partial water changes, heating his water, and dosing his tank daily with something like AquaSafe Plus.
If the tail has any blood or the edges are very white instead of sort of opaque white, then treat with the Fungus Guard for four days. Remove your carbon, keep the filter operating. On day 5, do a partial water change, and replace the carbon.
Date published: 2017-03-04