One of the ponds on the Austin Pond Society tour this summer had an old
clawfoot bathtub set up as an upflow veggie filter, with the pouroff
becoming a waterfall to the main pond. I'll see if I can find the
pictures; may take a coupla days.


And here they are!
http://tinyurl.com/lk8b/tub

Small versions and larger versions, depending on your speed/how long
you're willing to wait.

Pond is in south Austin, Texas.

Dale