Okay well I have a reef tank and I am thinking of purchasing a small UV Sterilizer to help with a brown algae problem. I just checked my phosphate levels and it is at 0. Actually, all my reading come at 0 including nitrates. My PH is 8.0, and I use RO water. I have a 55 gallon reef tank with a 29 gallon sump. I have a few videos on youtube of my setup if you would like to see it. http://www.youtube.com/user/Siwulam. The tank looks absolutely stunning right now, but I am noticing brown algae starting to cover things. I need to take care of this now before It gets ridiculous and my beautiful tank goes to crap. My question is the following: Can I put the uv sterilizer in the sump and will it work just as good as if it was in the tank? Also, for those who have had the same problems, will the brown algae completely disappear from objects? Thanks for any input. My light on my CF is on for 11 hours on a timer with no breaks, it is 260 watts. I am thinking of adding a first break for an hour at around noon. Let me know what you guys think.