On Thu, 19 Jun 2008 22:56:16 EDT, Phyllis and Jim
wrote:

Never tried one for a pond that big! The rule of thumb is veggie
filter = 10% of the surface of the pond as a minimum. More is surely
better! As I understand it, you need at least a 45 minute flow-
through time to allow settling. You can always divert some of the
water around the veggie filter to slow it up. Our veggie filters are
18" deep with EDPM liners.

And depending on your financial situation, a big vortex filter to catch the
solids before the veggie filter would mean the veggie filter would last a
long time without needing to clean it. ~ jan
------------
Zone 7a, SE Washington State
Ponds: www.jjspond.us