The larger the veggie filter the better, both in volume in surface area.
When having to decide between surface area and volume, surface area is
better. Surface area is the limiting factor on how many plants you can use.

I use a 2 stage veg filter, made out of two 55 gal drums. Pond water comes
from the bottom of the pond, into the first drum, at the bottom of the drum.
This drum is filled with sunscreen netting to slow the water down and filter
out any particles. From here the water goes into the 2nd drum through a
venturi nozzle, so it's aerated.

The second drum is filed with milk crates and more sunscreen netting (others
have used window screen netting, and polishing pads to commercial floor
polishers) From here the water goes into the waterfall. In both drums I
plant water hyacinth, and in the area behind the waterfall I plant mint.

Netting is a lot easier to use and clean, then lava rocks. With lava rocks,
you have to scoop them all out, hose the off and replace them. A task which
rapidly becomes not fun, because lifting rocks out of a drum gets heavy
quickly. With netting you just pick it up, lay it down on the lawn, hose it
off, roll it back into a ball, and put it back. 10 minutes verses all day.

Sameer


"Dave Hahn" wrote in message
. ..
I need some information on what a 'veggie filter' should be. Some say that
the surface area should be 10 - 20% of your pond. Others say that it
should
be 10 - 20% of the pond volume. Which is correct.
Also some say not to use lava rocks, others say it's okay.
What about water flow? How many gph should it have?
Should the pond water enter from the top or the bottom?

Here is what I think I am going to do:
Pond size = 1600 gallons
'Veggie Filter' = 225 gallons (2x10x1.5)
GPH Flow = 400
Pond water will enter from the bottom and cascade out the top like a
waterfall.

Will this work?