My 3600/gph pump pulls from a 70 gal stock tank that acts like a
settling tank. It has two 4" pipes coming into the bottom of the
tank. I got the framing material for making window screens and made
four 'screens' and screwed them together to form a four sided box
approximately 12"W x 18"L x 18"H. This sits over the two inlet pipes
and traps any debris before the pump. I have a 2x8 board on it to
weight it down and hold it in place. There are a lot of trees around
so I have to clean it out about once a week. Now that we are past the
cottonwood and maple seed time, I will only have to do it every couple
of weeks. This setup catches anything larger than 1/16".

/==========================\ - stock tank
/ \
| ------------------ |
| | screen box | |
| | __ __ | |
| | ( ) ( ) | |
| | (__) (__) | |
| | | | | |
| | 4" inlet pipes | |
| ------------------ |
\ /
\===========| |============/
| | - to pump

Michael Shaffer wrote in message ...
Anybody know how to make an inexpensive pre-filter for a pump? What if I
took a peice of pvc pipe and drilled some holes in it and wrapped foam
around it? I don't want to pay $150 for a filter, especially since I
want my veggie pond to get the nutrients. I just want to keep out things
like mud, acorns etc.

Thanks
Mike