Cecil, (I am searching right now) have you found anyone using an earthen pond for their system? It seems that they may be calling for a 2:1 ratio of plant bed volume to fish tank volume, but that would be a gigantic plant bed with our ponds. It seems to me that the ratio of nutrients in the water would be the same in a pond of 100 gallons and 1 fish, as it would in 1,000,000 gallons and 1,000 fish, so I do not see why it wouldn't work.

-Chris
1 acre pond
Currently managing:
FHM, GSH, GSF, BG, PS, RES, LES, YP, SMB, LMB, HSB, RBT, WE, CC, FHC, and Grass Shrimp