I put a four inch Clown Tang into my tank thirteen days ago and it has not touched any of the multitude of different foods I have feed the other fish. It will swim around with the other fish while they eat the food from the surface and through the food although it only chews at the algae on the back glass and water pumps? It looks quite healthy at four inches and is chased off and on by my similar sized Powder Blue Tang although it turned and snapped at the Powder Blue at one time. It constantly swims the length of the tank and it looks very healthy? Is it getting enough nutrition from the algae on the live rock, glass, and pumps? Any ideas on feeding?