On Mon, 3 Mar 2003 09:42:36 -0500, "BenignVanilla"
wrote:

What kind of rock is most popular in filters and why?

Rocks should stay in the ponder's head where they belong!

If I was doing a VF I would use a light grid (as someone mentioned in
another thread) several inches above the bottom and all my plants would be
in baskets anchored with big rocks sitting on the grid. ~ jan

See my ponds and filter design:
http://users.owt.com/jjspond/

~Keep 'em Wet!~
Tri-Cities WA Zone 7a
To e-mail see website