who uses U.V.? if so, what hours are you running it daily, or are some only using it to treat probs as they occur? i have 36w running on 800l setup. ran it 24/7 for a few days, now have it on 12hrs-on 12hrs-off cycle. makes the skimmer go nuts, i have it running sump - carbon reactor - uv - skimmer - sump.