Bio balls substitute ?

[paul]

I'm looking to replace/add to my bio ball collection in each of my 4 Bio falls. The blue bio balls that I have work well but are very expensive. I've used lava rock way back when and would rather not go back to using them. I've seen the banding/strapping used but It's also a bit overpriced. That leaves the sponge material that seems to work pretty well. If anyone could recommend a source for a suitable, firm sponge [already checked the Dollar Stores] that I could cut up into squares ,      I would appreciated it.

         Thanks in advance,
                                      paul

[dperry]

Buy filter material made of intertwined plastic fiber, such as Matala mat and cut it up into convenient cubes.  Bio-balls are approximately 1 cubic inch each.  One half-sheet of Matala mat is 24 inches by 39 inches by 11/2 inches, which is 1404 cubic inches.  The intertwined extruded threads of plastic that make it up probably has about the same total surface area for bacterial growth as the bioballs.  This means that the sheet of Matala would be equivalent to 1404 bioballs. The sheet is about $25.  How does that compare with what you currently pay for bioballs.  The Matala is sturdy and long-lasting. I use it for my filters and it lasts for years.  Here's a link to one source that I use: http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=15799 

Don Perry