My 4 year old betta Abe has this odd white infection on his body at the root of his dorsal fin. I thought it was fin rot, so I moved him to a smaller tank and did daily water changes but he has not improved, he has gotten worse over the past few weeks. It almost seems like his scales are rotting off, and his color is definitely dull. Other than that, he seems fine: he's eating and swimming around normally (a little slow, but probably due to age: he's an old man!) please, any help would be greatly appreciated! He normally lives in a 5 gallon tank that is heated and has an air pump (no filter but the water is circulated).