I should also mention that small manual removal of this algae is useless. I struggled with this algae for AGES that way. It will grow back very very quickly. You need to shock and awe the buggers into submission. I've searched endlessly on the web and forums for a good guide to remove these guys.. I couldn't find one. So this is straight from trial and success! Need to remove every single speck you can see, and water changes i made was 40-50%. While sucking out water... I also suck up every bit of the algae I can see floating around. No mercy!! Once it goes into remission and weakens its grip, it slowly dissapears. I dunno if it dissapeared by itself or my critters ate some, and I dunno why my critters didn't eat them up before I perform this routine. maybe they got too thick and tough to eat. Mystery to me.