Oh ya.. just in case anyone is wondering what is so bad about hair algae.. well.. the hair algae itself isn't all that terrible.. it is all the crap that gets stuck in it that fouls up the tank that makes it bad. I must have had 100 hermit crab corpses without shells stuck in the hair algae. Just cleaning up 1/3 of the rocks I can already see the few surviving corals starting to appreciate it a few hours later.