Potassium Permangate is NOT an Medicine it is a strong oxidizer i have seen people actually try to help there fish with this and kill them quickly,
If this is a Bacterim i would suggest a Antibiotic like Cephalexin or Ampicillin which is available through Foster and Smith,
But i wouldgive he sterilizer time to work,
Here is an article i usually reccomend,
Tail and fin root is a fish disease caused by bacteria. Normally, this disease will not infect healthy fish living in good conditions, but poor health and poorly kept aquariums are not the only causes of tail and fin root. It can for instance be caused by injuries and other fish nipping the fins or just generally bullying them; all which weakens the fish in a way that allows tail and fin rot to infect them. This means that it isn't very hard to prevent or at least minimize the risk of tail or fin rot in your aquarium. All you have to do is to keep the aquarium clean and well kept; the fish healthy and well fed, and only combine fish that gets along well. Tail and fin rot can also be caused by Tuberculosis which can be harder to prevent. It is important to determine the cause of the disease when treating it and rectify the problem otherwise the disease might return within a few weeks.
The main symptom of fin and tail rot is exactly what the name suggests; that the fins or tail starts to rot and disintegrate. In severe cases there will be nothing more than stumps left of them. The disintegration of the fins often leaves exposed fins rays and the disease can also cause an irritated area around the base of the find and bloody edges on the fins. Tail and fin rot can also generate symptoms on other part of the fish body such as skin ulcers, loss of color and cloudy eyes. The skin ulcers usually have red or gray edges.
External treatment by antibiotics is usually enough to treat this disease but the disease can be internally medicated as well. Which option you choose might depend on the size of your aquarium etc as medicating the water in a large tank can be expensive. If you choose to internally medicate your fish you should mix 1% antibiotics (chloromycetin /chloramphenicol, tetracycline Cephalexin or Ampicillin ) in the food. Make sure that the fish eat the medicated food. If you decide to medicate the water you should add 20-30 mg per litre water of the same antibiotics I mentioned above for internal treatment.
