FAQ: Does the Biological Filter Ever Get Clogged Or Need to Be Cleaned?
No. Because we cover our biological filter tubing with at least 9" of expanded shale (our preferred filter medium), debris simply cannot get down to the tubes to clog them. We have NSP's that are 15+ years old that are functioning better than ever and have no suction loss from the filter! We do recommend that you net up sunken leaves and vacuum the surface of the planted filter area with a pond vac at least once each year during Spring Cleaning.