I think it depends on the yellow tang, mine would rather starve than eat anything green. From what i heard they are one of the worst tangs to have as far as algae consumption. But then again i think it depends on the fish. Im in the process of capturing mine so i can trade him for something that will eat algae. Lawnmower blennys ive heard are good, ive had one but my mean tang chased him right out fo the tank and onto the carpet after the first day.