UV sterilizers

[foxface]

What's everyone's take on UV sterilizers. I've read plenty where they are being sold but I'd like to hear from a practical point of view. I've heard you can run it only during the day with a timer so you don't kill the good bacteria that come out at night, does that sound weird? I'd like to put one in the sump but I don't want to buy one for nothing. Some people seem to swear by them and other don't...
Louise

[Teeka01]

What I have been told is to run a uv for just 2 hours a day. By what I understand the good bacteria is out all the time. I could be wrong tho. I know it seems like I don't know much. I have only been in the hobby for 4 months.

[Murfman]

UV sterlizers will kill anything, good or bad, that is in the water column. If it were a fish only with live rock, I would say go for it. I run ozone, but only for 1 week a month to reduce contaminates in my water column.