"Webfoot" wrote in message
...
I am using a laundry sink for my upflow filter. Why cant I just hang
a UV light over it and save $200?

Russell Mack

If you are using it for a biological filter, the UV light would defeat the
purpose. Even a mechanical filter does some bioloicial filtration. Any
beneficial bacteria living on your filter substrate will be killed, and likely
cause you filter to become clogged more often. UV light kills bacteria and
other pathogens (including good bacteria). It does not remove ammonia,
nitrites, and nitrates. The UV light used as a filter is short wave UV, not
your typical black light. If you have a UV shortwave light, and want to use it
in the way that you suggest, I would recommend that you use it over a tub/sink
that isn't used for a filter per se, but is simply a holding tank through which
the water will flow while it is being irradiated. And it is very important that
the UV light not flood the surrounding area (such as the pond, on plants, or in
your eyes or skin), as it can cause damage. The UV should be the last part of
the filtration system before the water goes back into the pond, or
alternatively, you can either use a separate pump for the UV filter, or divert
part of your pump's flow to the UV filter. Oh, and make sure that the light is
water proofed.