I had an awful outbreak of hair algae in my 55 reef. While I got the conditions under control, I found an amazing algae blenny. I had wanted one for awhile, so I added him. He went to town on the stuff. He had about half of it consumed the day after he was added. Was pretty impressive to watch him go to town on it. My clowns weren't to happy as they were living in the stuff, that is how long and thick it was! But what was stated by melsou is right, you need to get the underlying issue under control as well. Mine was being fueled by bad water and overfeeding, which is pretty common. I just love corals and want to feed them to get bigger corals! Was a hard habit to break. But through manual removal prior to water changes, RO/DI water, minimizing feedings and stopping feeding my corals was the key to winning this battle. The algae blenny was just an awesome addition that helped me out when I wasn't shoulder deep in the tank. He is still nice and fat, months after getting control of the problem. One of my local SW pals actually just dropped her lawnmower off as it was withering away. He is working on the algae in my FOWLR tank and doing well. The point of me saying this is using a blenny to solve the algae issue won't work. At best it will remove it, starve to death, and the algae will return if something isn't changed about your system/management.