1 U.V. or 2?

For all of you that had pea soup, bought a uv, and now wonder why it
took you so long, what kind of filter do you have? What's the media? how
big is the filter?

I have a big Oase BioTec 30 rated up to 30,000 gallons (10k with
fish).

Great filter for ~1200 by the way. Does an immaculate job filtering
the water, even filters clay and will clean my fully muddy/murky
12,000G pond out in 24 hours and crystal clean within 72.

I like it most because it's the easiest to clean filter I have. I
didn't want bead because I've heard they won't filter everything as
good.

To clean the Biotec 30 you just open the drain to drain it a bit so no
more water is flowing out of the filter, but a bunch of water is still
in it. Pull the japanese wire mats out, rinse the bio-pads under the
incoming pond water, reinstall them, shake the wire mats inside the
filter in the open space / dirty water up and down, drain the entire
filter with the bottom drain and re-install.

Takes about 10 mins, maybe less. It's easier to clean then my
aquarium filter.

I don't know exactly how much I need to clean it yet. Once a week
(unless there is a reason) seems to be too much and 90 days too long,
I'm thinking probably once a month to clean it unless it's got a lot
of stuff to filter.