Hate to keep beating a dead horse, but they have great sea hares for this problem that are reef safe. I had some really bad red slime algae break out in some of my prop tanks while they were cycling. It was all over my frags to the point that my zoos wouldn't even open up. I used 3-4 sea hares in the various tanks and a phosban reactor. 2 weeks later my problem is almost completely gone.
My hares are great they'll eat diatom, red slime, hair algae, small caulerpa, gracilaria, another one I don't know the name of, and who knows what else?? They don't like hard macro algae tho (kelp looking). Just trying to let you guys know that you can end your suffering if you choose to. LOL
But at least use a phosphate remover if nothing else!! ;] Get rid of the excess nutrients and your algae will stop growing too.