I was looking in my pond yesterday and noticed that one of my big guys approx 12-18 in has what looks to be like a red/yellow spot on the back of his top fin, it looks about the size of a quarter, any one know of any sites i can look up to see whats wrong and how to get it taken care of. I figured i should pull him from the pond and put him in quartine, with a salt solution from the little i have read, but i want to know excallty how to handle this before i do anything.