if you look closely you can see a single white dot on the side of my orchid dotty back, all the fish in the tank were quarantined a minimum of one month and I have never seen signs of disease, however I recently introduced a Y. Corris Wrasse after one month in quarantine and he was chased and harassed until he found a way to jump through the mesh at the back of the tank and onto the floor, but I never saw signs of ich on him alive or dead. Any ideas or input is most welcome.