David Larson wrote:
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



--
dont know of a formula for a TT but we have built two the first is about
the size of a large 5 gal bucket made solely of lava rock the second we
used three milk crates and glued the lava romck to the outside

after plumbing we filled both with loose lava rock

pics of both on myu website below




John Rutz
Z5 New Mexico

good judgement comes from bad experience, and that comes from bad
judgement

see my pond at:

http://www.fuerjefe.com