The heart of a filter is its filter sponges – filter cartridge set for the BioTec Premium 80000. 2x violet filter sponges included in the set have rather coarse filtration properties. The higher flow speed is particularly beneficial for the oxygen-loving filter bacteria. These microorganisms ensure that the degradation products produced in the pond are converted into harmless substances (nitrification). This also applies in particular to the two blue filter sponges included. The two red filter sponges, on the other hand, play to their strengths with fine filtration properties and thus remove the smallest dirt particle residues from the water at a slow flow speed. The ideal team performance for your BioTec Premium with perfect filter results.