On Fri, 18 Mar 2005 21:26:23 GMT, "George"
wrote:

My brother has a large partially in-ground swimming pool. He forgot to drain
the filter one winter, and the water froze and broke the backflush valve.
Because of its age, he decided to buy a new one instead repairing this one, so
he gave it to me. I just needed the tank itself, so I stripped out the guts and
converted it into a biofilter.

So what you have is a pool filter with a more coarse medium than
sand?? I often wondered how that would work.

Regards

Hal