I use run a 40watt UV sterilizer for 8 hours after the lights go out at night.

I used one on a fresh water tank and it worked great but the research I have done for saltwater says that they can work but if you are running additives like Zeovit to not use them. I am running Biopellets so I haven't tried the UV Filter as of yet. I think with a UV filter you are trying to contact as much of the water column as possible so meaning it has to be a large Filter to do any good. That said I haven't used one on a reef tank so I am just speaking from research i have found. Good luck and enjoy