12 or 24 hour UV?

[Mr.Reefer]

Some people say is not good to run a UV sterilizer on a reef tank 24/7, other say that is ok.

What is the true about this?

I run mine 24/7 in my 75g, and 12h on my Aquapod

[naldopr]

basicaly you are killing both benefical and not benefical bacteria.
justlet it run for a couple hours aday or once a week...

[ScubaDave]

UV does remove some harmful things from the tank however it can also take away nuterients and other things that are good for the fish. It's best to run it every while to stop a build up of the harmful things but not to run it constantly as that will simply serve to take away the benefitial bacteria.

[whynotfive]

I would have thought that a more natural approach would be the most beneficial. Trying to emulate natural conditions, and that means not running it for even 12 hours a day.

[jonnyjamms]

UV does remove some harmful things from the tank but it can also take nutrients and other things are all good fish. It is best to run it each time to stop the establishment of harmful things, but do not run it constantly.

[Damien53]

I was constantly fighting a brown slime algae problem in my reef tank for months despite having no detectable levels of nitrates or phosphates in the system and vigorous surface agitation to keep oxygen levels high and carbon dioxide levels low. I guess I could have had defective test kits but these readings were consistently 0 and I was still having these algae problems! I decided to try a UV Sterilizer in my tank after reading how pond owners use them to control algae in their outdoor ponds. I figured it could only help my tank. Guess what, I noticed a difference after the first two days of using this sterilizer and the amount of algae in my tank has been under control since. I'm using the 15 watt Aquastep UV Sterilizer that hangs on the back of the tank. There are better, more expensive models but this one seems to be doing it's job nicely.