Hello, New to forum. I recently purchased 1 Male Guppy from a Pet Store in my town. It has a purplish white area around its top fin. I have it in a separate tank by itself. I have treated it with Rapid Cure for 3 days then I have been treating it with Melafix for the past 5 days now and it is still there. Any one know what this might be and how to get rid of it? He was not showing any signs of illness other than the purplish white mark around its top fin. Thanks.