I'm sure this will get some interesting replies and I think I know the answer but I want to hear it from you all first. Just because a fish is exposed to ich/velvet/brook, does it automatically carry the disease, even if it doesn't show any symptoms/isn't affected by it? I've had a foxface rabbishfish for three years whos been exposed to ich and velvet and has never shown any symptoms which is why I am asking. I am cycling my 300 that crashed due to a fish bringing velvet in. He has been in a QT now for 5 months with 2 other fish and none of them show symptoms of anything. The only treatment they have received was prazipro+metroplex. I don't want to put them through copper if it isn't necessary.