Ok I have a 50 gallon tank with 8 fish, a powder blue tang, copper band butterfly, maroon clown ,wrasse and some other small guys. My problem is I think the Tang and Butterfly have ich. At first I thought it was sand stuck on them as there is plenty blowing around the tank but I saw the tang scratching today ( if it was sand would he scratch to get that off?) Anyways I know I need to set up a quarentine (should have done it in the first place) But If I set one up it's not going to be cycled and if I put all my fish in there I will have ammonia and nitrites that will kill them all anyways. The fish are all still eating great and my water is perfect, even nitrates are 0. What should I do?