"Gale Pearce" wrote in message
...


Hi, was wondering if someone could tell me if I did the right thing here.
I
built a Biofilter for my pond.It is 12X7X2. The one I built is 9gal.
basically a square Rubbermaid box. The pump (1200gph) pumps into the "top"
of box through an 18W UV light, then goes into filter through a 1 1/4"
thick
Med. filter pad. It works its way down through the filter media. The media
Hi Paul - IMHO, you have the right idea , but the filter is a bit small and
will need cleaning more often than I would like - My pond is close to the
same size as yours with ~ 40 fish , but I use a 45 gal barrel with a 1200
gal pump (upflow design) and I need to "backflush" it 2 - 3 times a season
when it loads up (no UV, but the UV only helps with algae bloom anyway and I
never have it when my filter is running) Also 1200 gal/hr is a lot for a 9
gal filter to work properly. You will know how it works when you test the
water, or to be safer go to a larger container and add media to it as you
need it (or get tired of cleaning it so often)
Gale :~)

Hi Gale:

If you install a pre-filter in front of your main filter, you won't have to
flush the filter at all or at least only ocassionaly (which is even better,
because the microbes in the main filter will remain undisturbed, will grow more
profusely in the filter media, and will clean the water more efficiently). Then
every time you notice that your water flow out of the main filter is retarded a
little (usually about every 3-4 weeks on average), simply pull the pre-filter
out and clean it Here is a link to a page which describes my filter set up
(which is similar to yours in function), and shows the details of the
pre-filter. The trick is to prevent detritis from building up in the main
filter, and only allow pre-filtered water to flow through the main filter. That
way, you are reducing the nutrient load to a level the main filter can quickly
digest, and won't suck up particles into it that cause it to clog.

http://home.insightbb.com/~jryates/filter.htm

Scroll down until you see the pre-filter. I use a commercial pre-filter, but
you can easily make your own.

Enjoy.

George