The Aquascape UltraKlean BioBalls provide pond owners with efficient mechanical and biological filtration, optimizing water conditions. The significant surface area of each UltraKlean BioBall ensures effective colonization of bacteria, maximizing biological filtration in the filter. Mechanical filtration is provided as the UltraKlean BioBalls create small channels by packing together, leaving behind unwanted debris. During backwashing, the BioBalls are easily stirred up to release debris for removal. 250 BioBalls are included in each box. Aquascape UltraKlean BioBalls are intended for use with UltraKlean Pressure Filters. Aquascape is passionate about the products we produce, providing unique products, designs, and features that stand above the competition.