No. Do not add a filter pad, filter mat, foam, or other filter media inside an Aquascape UltraKlean™ Pond Filter.
The UltraKlean is designed to operate with UltraKlean BioBalls as its internal filter media. The BioBalls provide both biological and mechanical filtration and are designed to be cleaned through the filter’s backwashing process.
Additional UltraKlean BioBalls may be added if more biological filtration is desired.
Use the UltraKlean only with UltraKlean BioBalls as the internal filter media.