I Have a green terror about 6in. It looked like he had like a little polyp or white dot on his head. couple of days later it turned into a hole. It looks red around the edges. my water parameters are fine. the only thing I can think that might be the problem is the feeders. its not that much. i give him feeders like twice a month as a treat. rosie red minnows to be exact. It looks like it is spreading fast. one big hole in the center of his head and one lil one right next to it. any suggestions. so far i did a water change and added salt. do i have to quarantine him?