Colapera (I am not good at spelling). My hairy algae problem only started when I removed a golden plant that would continusly grow and I had to harvest it. The plant came attached to my live rock-man what a mistake it was to get rid of it!!!!!! The hairy algae got soo bad that it over grew my corals and chocked them off. I want as far as removing all my live rock, killing it and soaking it in hot fresh water and it still came back (all my tests are in line-amonia, nitrate, nitrate, etc. I also purchased one of those so called "Janitorial" crews of red legged crabs and mexican snails-again a waste of money. IMO the only way to get rid of the algae is to get plants that compete for the phosphate. They don't make enough phosguard to get rid of hairy algae once you have it-and remember I only have .2 ppm. Fish and remaining coral (bubble and star polp) and anenime are doing fine. But I still am fighting hairy algae. I just put in the colapera. By the way the Kent RO/DI came with a charcoal filter. I never read that it was activated charcoal, because if it is not, it has a ton of phosphate in it. Hope all this helps.