I'm getting some kind of algae all over my sand. No matter what i do helps. I'm using RO water from LFS and tried the stuff from Walmart's water ro fill station thinking it might be the water. Still no help. I am running a octopus skimmer on my tank and pulls some good stuff out every 3 days. I feed my fish about every other day. I have tried doing multiple water changes. I have even sucked the stuff out and keeps coming back. It only grows on the sand. I have a 29 Gallon 130 Watt Current USA light on for 10 hours a day. Will post water prems in about 30 mins. What can i do to get rid of this stuff once and for all?