uv sterilizer

[oscarslr]

what is the purpose of it, and is it beneficial to have

[jer77]

Well, UV sterilizers alter the DNA of free-floating pathogens that are in the water. This pretty much kills them. This is for killing bacteria, good and bad, algae, parasites, viruses to some extent, and fungus. It is beneficial to have on large tanks with many fish where these things may become a problem. It is however not a cure for diseases because it only kills things that are free-floating. It also may have an impact on populations of good bacteria and phytoplankton, zooplankton and such. So for most reef tanks uv sterilizers are not used. They are mainly for fish only tanks or holding systems.

[alkataz]

What your uv kills depend on what rate you run the water through it. Individual uvs have different flow rates. If you run them at the higher end of the flow rate spectrum you kill things like algea, but if you run it at the lower end then you begin to kill the parasites, because you need the longer exposure time to truly effect parasites.

I usually run mine on my tank for a week after adding a new inhabitant. I tipically QT all inhabitants, but I run it as a extra precaution. I use to run it 24/7, but one day after maintanence I forgot to turn it back on and didn't notice for a while, but I saw no real change in water quality so I didn't turn it back on. When I use to run it 24/7 I had a good pod population, but I also had two HOB fuges as well so I don't know. I had to mandarins and they did just fine while it was running.

[greenbean36191]

As hobbyists use them, about the only things they're useful for are breaking down organics into forms that are easier to remove and clearing up green water. Even with extremely low flow rates the units available in the hobby generally aren't an effective means of controlling pathogens in a reef tank, be they bacterial or protozoan.

[alkataz]

I don't use mine to break down organics. I run some ozone through my skimmer. And yes it is good for getting the green tint out of water. But if you are having an algea bloom or if your fish are sick I think you would be better off hospitalizing the fish, or finding out what is causing the algea bloom ex. excess nutrients and taking measures to fix the problem.