Using A Uv Filter Question

[star4]

I was having some trouble with one of my tanks and decided to add another filter, the one I bought has a uv light inside. However there are no instructions about using it.
Do you just switch the uv on and leave it on constantly or is it 12 hours on 12 hours off sort of thing?

Thanks.

 

[OldMan47]

The UV kills the organics that go past it while it is turned on. The amount of time that a particular thing needs to be exposed varies quite a bit so the flow rate vs the light intensity becomes important depending on what you are trying to control.

 

[star4]

Mostly for algae control, the tank always seemed to look almost cloudy but it wasnt cycling. The uv external filter is a 2000l/hr flow rate, but I am also running a 1100l/hr external and a 1000l/hr internal on a 300l tank. (was running 2 x 1100L/hr externals but swapped one for the uv filter).

It has been running now 4 days with the light on and the tank is now crystal clear and all the stats spot on so the light has worked, so I am a bit worried about switching the light off, but also worried if too much of the uv light is a bad thing.

Thanks

 

[star4]

Anyone? do I switch it off now the tank is clear?
Thanks

 

[OldMan47]

If you no longer have anything to control with the UV, you might as well switch it off. UV lamps do not last a long time in use so if not needed they should be left off. That way there is still some life left in the bulb when it is switched back on. I would remove the UV completely from the water system but I have no idea how to do that with a built in lamp in a filter.

 

[star4]

Cheers, taking the lamp out of the filter is not a problem, but I will switch it off and leave it for a week or so just to make sure the algae does not come back. Thanks for your help