Therehas been so much discussion involving UV sterilizers over the past years. The small home aquarium type UV is basically useless, unless you get into high wattages and tremendous tank turnover. And then you are killing a lot of the desirable things in your water as well.
Here is a myriad of discussion on UV sterilizers. I just hate to see someone waste their money, and invited him to discuss why he wanted one.
uv sterilizers