I can't post links to other forums here, but do a search on the web about dosing Kent Tech M (Magesium) for hair algae control as well. It is safe, we've done it. I'm not a fan of resorting to chemicals, but the Tech M treatment really does work. The problem with using a blenny, or a sea hare or a ton of snails is you have to figure out what to do with these creatures once the algae is gone, because they very often will starve. Some sea hares/blennies will accept frozen or algae sheets, but many do not. I tried a sea hair, it cleaned my rocks of other things, but not the hair algae that I wanted it for. Tried a baby fox face, and while he is working, he's now discovered that there is a supply of good being offered daily and doesn't seem as interested in hunting for his algae.