In your tank but not mines. I never introduced ich into my tank.Yes. However my tank has been running for 1.66 years, the newest corals dipped and fish were qted at the store. My 1.5 year old Blue eye Kole tang who was most likely 1-2 years old when he was in the shop (1-2 years old when he was brought into captivity)still got Ich (Yes he fought it off before we could dip him). Ich can still pass through QT it will always be in your tank. Either lying dormant and waiting for the time to strike or active and you’ve just never noticed it (The tang was the fourth addition after a CBB, two clowns and a Foxface rabbit)