"matrix j" wrote in message
...
I am wanting to make a biological prefilter out of a large flat
rubbermade container using some coarse and medium density pads and
springflo for the bio medium.
The pre-filter will be placed at the bottom of my pond.

I have the Tetra PF1 in the in-pond intake filter version from eBay for $61
from reefboy0001 including S&H.
If your labor is worth anything to you this is a good deal.
It cleared all the sediment out of the water in short order. It has
bioballs, a carbon pad, and a white poly pad. I added poly quilting.
One strange thing did happen. We had a big storm and when I returned home
the intake filter basket was floating in the pond. The neighbor had
switched off the pump, so it was okay. I never did figure out what made the
tub float to the surface. A big rock and two 1/2" [1 cm] holes in the bottom
should fix that without compromising the flow rate.
--
Crashj