z28pwr- Wow! That's a very green tank. Have you checked your phosphate level? The phosphate test kit from seachem is an excellent kit. It measures all the way down to zero, many other kits have a lowest reading of .2 which is still too high. I had a lot of problems with green hair algae in my own tank until I got the seachem test kit and used phosguard to bring my phosphate to below .02. Natural seawater levels are .01 - .03 mg/l.