[Rob Tetrazona]

What size tank do you have? I had gw in my 75 and borrowed a 9W UVS from a friend of mine. It took about a week to finally clear up, but it did work and after returning the UVS back to my friend the gw did not come back. My friend recommended that if I ever buy one it should be atleast 18W for a 75 gallon tank to get quick results.

The other cool thing was that he had it rigged up to a power head and old filter parts. All I had to do was hang it on the front of the tank, let it do it's thing, then take it off once the water cleared.

 

[Rob Tetrazona]

I have a 5 watt on my 52 gal and it works great. I think the problem with your system was that you had the water going through the UV too fast. UV kill is a function of exposure time. If you slow down the flow rate, you increase the kill rate. My UV's flow rate is only 50 gal/hour but even at that slow rate it will reduce the algae level by 1/10,000,000 in 24 hours.

Thanks for setting the record straight, RayThePilot. This is useful info.

 

[Rob Tetrazona]

Yeah, man. UV sterilizers are a lot easier to use than blackouts and water changes to treat GW.