Need Help With UV Setup

[readingbabelfish]

I have had a 75 gallon reef tank going for about a year. I have a few easy corals like zoos and an acan colony. Every day I have an outbreak of red cyano bacteria. It appears on the sand when the lights are on for about 2 hours, then disappears after the lights shut off. All my parameters are good, so I have decided to get a uv sterilizer in hope this may help this problem. My questions are these: Which uv should i get? How do I run it on my setup? My set up consists of an Eshopps overflow box that has two outlets, one outlet runs through a 5 gallon bucket filled with sponges into a 20 gallon sump, the other oultet just runs straight to the sump. Both lines have ball valves so I can adjust flow. My sump has a heater in it, and a return line using a magdrive pump to the tank with a split line that runs back into the sump that has a ball valve on it so that I may control how much sump water is returned to the tank without putting any backpressure on the pump it self. I also have a protein skimmer hanging on the back of the tank. So where would I setup my uv sterilizer, the sump, or inline with one of the overflow lines, or just run a new line off the back of the tank through the uv and into the sump? What do you guys think? Thanks a lot for the replies!

[swat389]

Mine is above the sump. Here is what I mean. My sump is in a cabinet below my tank I took the actual sterilizer and atached it to the top of the underside of the cabinet. I ran a seperate small pump and hose up to it and i have my outlet flowing into my filter sock. that way the water flows through my sock twice. i still get a little bit of red on my sand with its use.

[reeferbill]

I had a problem with cyanbacteria so I siphoned it out with airline tubing and added another power head to that area of sand it use to grow at and now its gone. Try adding more flow to the deadspots after you siphon it out,goo luck. Happy Reefing!!!!!!!!!!