I have a 18500G pool I am converting to a big pond. Want to go as much
natural bio veggie filter as possible to keep the water eco clean and
transparent as in "Green", but not green water. I have enough pump and
mechanical filter to flow about 8000GPH, but veggie filters need it slow
and steady, right. I have enough space to make the veggie filter about
1/3 the surface size of the pool. Since I am in Phoenix the idea of a
large wet garden up behind the pond really appeals to me.

What would the ideal size be, surface and depth, for my veggie filter?

Chip