UV steralizer? Is it neccasery?
 

Is a uv steralizer benaficial or is it a disadvantage to have.
What good and bad does it do to a reef tank with heavily stocked sps , lps and softies for a 33gallon tank?

I've never had one but I've done a lot of research. My research shows that they do make a difference. But spend the money and get a good one like the Pentair Step one.

I've read that they can also kill beneficial critters along with the bad stuff. But they do make your water shinier.

They can kill good and bad but to me the bad out weigh the good so i ahve used one for 2 yrs now!