I have a yellow and blue tang that think hair algae is better than steak and tail...so you might try one of them....they will turn their nose up to brine shrimp and flake food if I happen to pull some out of a buddies tank and bring it home. You might consider one of them....but I would only add one and it will probably eventually outgrow your 55 gallon...which makes a great excuse to get a bigger tank...lol