yes i do have one of my tangs in a 3 gal tank, with a clown too. i recently got some new fish for Christmas from my girlfriend and she wanted to see them in the tank with the other fish. well go figure one had ich. my cardnal, another clown, and mandaran died. but i have 3 left. my yellow tang which was obligated to get ich from the first contact, one of the clowns that had ich to begin with, and a blue damsel. i couldnt catch the damsel so hes in the ich infested tank still. but my tang and clown are in the qt all getting along.