I've had one for about 3 years, first in a 10 (as the only fish), now in a 20L with other TINY fish. He's great. They do eat algae, but will also eat pretty much anything you put in the tank. I think it would be fine in your setup. The only downside is that mine has been known to nip occasionally at my acan hillae. Maybe he was after something besides the coral, who knows. I moved it to another tank and all was happy again.