EHEIM Pro Substrate: Biological filter media for optimal biological decomposition.

After mechanical water treatment by EHEIM Mech, the Pro Substrate provides essential cleaning bacteria with the best colonization conditions thanks to its high density, spherical shape (fully utilizing the volume), and ideal surface structure (maximum number of bacteria per sphere). This combination results in a maximum number of cleaning bacteria, ensuring clear, healthy water and stable water conditions that extend filter life. The Pro Substrate reduces nitrite pollution spikes and is washable and reusable.