okay so, I have had ich in the past due to not having room for a quarrantine tank, and in my experience the ich is visible for a day or 2 then it drops off the fish and multiplies. Ever since I moved house a year ago ive been able to put a quarrantine tank in the spare room. so I took all my fish out of my display and into a quarrantine tank, treated them with copper for 30 days and left them in the tank for a further 42 days to make sure the display tank stayed fallow for 72 days total. I put all my fish back in and I hadn't seen a single spec for 6 months. fast forward to last week I decided to buy a powder blue tang as its a fish I've always wanted to try and I had gained confidence in my quarrantine procedure. Go to check my display tank and find that my coral beauty has a spec right in the middle of the left side of its body! I've checked it every day since then and the spec is still there. the fish is still eating normally and she's nice and fat with full color. I checked her fins thoroughly and couldn't see a single spec which is weird to me because everytime I've had ich it always hits the fins first. I also have in the tank, a sleeper goby, 3 clowns and a chromis and not a single one of them has any spots. I checked again today and the spot is still on my coral beauty after a week, and I'm certain its the same spot because I took a photo of the fish and marked it up exactly where i saw the spot as the spot wouldnt show up in the photo. I know its highly unlikley that ich would last this long on a fish but i just wanted some opinions because im freaking out that I might put this powder blue tang in after a month and a half of quarrantine just to end up back where I started. any input or opinions would be appreciated.