This information would be a lot more helpful if you included your tank size.Hey fellow reefers, I had a huge problem with hetero bacteria, which you may see in my profile, I did some things that other fellows reefers told me as well as my lfs, but at the end nothing solved the problem except of a UV unit. I didn't go to anything fancy and costly, I just installed a very low priced Chinese uv in the 7 watt range
and I used it for 2 weeks, my tank now is crystal clear!!! I may used it again when the tank will come to the point where it need it. For that reason I vote it is just right! After all a uv may only give us good things and not bad things as I understand it...