The work that has been done with bead filters shows that 1 cubic feet of
beads has 400 square feet of surface area and it is rated to support about
50 pounds of fish. But all filters are overrated by at least double. The
tests were done in an aquaculture situation without all of the extra debris,
and with controlled feeding.
--
RichToyBox
http://www.geocities.com/richtoybox/pondintro.html


"David Larson" wrote in message
...
RichToyBox wrote:

David,

As for whether it is best for the water to run upflow or downflow, a
well
drained downflow, free to allow air into the media is probably the best
and
is known as a trickle tower. If the filter is full and used for plants
on
top, then upflow is easier to plumb and maintain a water level. The
bacterial surface area is the same, the difference with trickle tower is
the
additional aeration available.

Thanks for the reply! Your idea of the trickle tower makes sense, seeing
how this is the method
used in sewage treatment plants.

My next question is this -

Is there is a formula to figure out the cubic feet (or surface area) of
filter media one would need?
Let's say the pond will be 3,000 gallons.

- David