Here are a few suggestions for screens:
http://www.aquaticeco.com/subcategor...ders/divider/0
http://www.petsmart.com/product/inde...ductId=2753067
http://www.aquaticeco.com/subcategor...ders/divider/0
The screens by Lee's are more pliable and have more holes. The screens by Penn-Plax are stiffer. Give the idea a try and let us know how it turns out.
Good luck!