I found this on wetwebmedia.com:
Brown hair algae
I have a 72 gal bowfront w/ approx 60 lbs of live rock , a 4'dsb , a AquaC remora pro skimmer, 2 250 MH 10000 k , and CSL t4 hooked closed loop to a SCWD. also I have a chiller and Eheim 2227 wet dry.
enough about tank, recently I have had an explosion of brown hair algae growth, I don't use ro but the only thing my tap water "deep well" is high in is silicates, my tank levels run around.06 <Youch that is very high. And silicates can feed some types of algae growth.>
I have no detectable ammonia , nitrate, nitrite, or phosphate.
my sg is 1.023
chiller set at 78
I add tech cb for calcium
I ad strontium and iodine.
what is causing the sudden explosion of growth and how do I stop it,<The silicates definitely may be feeding it. I know I had to remove some sand with silicates in it for the same reason.> is a ro going to be a "silver bullet" at this , I don't have room for the ro collection drum in my home, I would love to get an ro though, <Understandable.> is there anything that will eat brown hair algae? I currently have a yellow tang and a lawnmower blenny. <I've had turbo's that would eat it but I didn't get the impression they liked it as they moved through it as fast as possible. I've also been told green Mithrax crabs will eat it.> as well as snails and hermits. I haven't done any drastic changes but just had an explosion in hair algae growth and the tang, blenny, snails wont touch the stuff. I have heard that a lettuce nudibranch will eat the hair? <They will eat Bryopsis, perhaps you need to go to algaebase.org and make sure what you have is brown hair algae?> if what will, this stuff has covered 30% of my tank in one week, I try manual remove but don't even make a dent, it is attached so hard I have to use tweezers. <I have taken a bucket of salt water and scrubbed every rock etc and then returned them to the tank before. You don't mention what your ph is. Dripping Kalk seems to help get rid of hair algae by raising and making more stable your ph.> any help would be greatly appreciated. <Let me also suggest you read through these Faq's and see what you can find there to help as well
http://www.wetwebmedia.com/brownalgcontfaqs.htm Good luck, MacL>