To UV, or not to UV, that is the question

[Evilweevil]

I have had once running ever since I set up my tank 4 years ago and I can definetly say I don't know if it really makes a difference , I just go on the principal if it's working just keep doing what your doing is all

[dino]

I like to run it when I add fish

[Myka]

I voted for all the answers. On my own reef I don't use UV at all, I have no reason to. On my client tanks I have some that don't use UV, some that use UV part-time, and some full-time. Depends on each tank, and also the client too (I put big UV sterilizers on tanks where clients add non-quarantined fish). I like to have a UV sterilizer available to use on tanks that have Tangs so the UV can be switched on if there are any Ich spots noticed on any of the fish. In order for UV to be effective for Ich, it has to be a big UV though, and there is a significant cost associated with a piece of equipment that is only used part-time.

[neeper]

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

[Allpointswest]

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