I know we discussed some cheaper alternatives to buying the over priced filter replacement sponges last summer. There is quite a selection of different kinds on e-bay. I just put an order in for a 15 foot roll of filter foam that is specificly for pond filters - $11.99. It sure beets the $9 they charge for the little 9 inch square that's sold as a replacement for my pump. 15 feet should last me a while!
We bought new sponges last year - ouch!!! Another thing we use during the spring algae bloom for additional media is quilt batting...You can get a huge roll a Walmart for next to nothing and it lasts a long time. Works great too! Thanks for the ebay tip!