Filtration foam 20ppi for crystal clear water; for use in the API Filstar xP. The 20 ppi foam pad is an ideal thickness to filter large waste particles (1st step of mechanical filtration). ppi=pore per inch. Maintenance: Every month wash the foam pad thoroughly in a basin of water taken from the aquarium. Replace the foam pad every 3 months. Never replace all the filtration foam pads simultaneously so as to ensure optimum biological balance. Instructions: Place foam pad into the bottom filtration compartment.
Fits API XP1, XP2, XP3 and XP4 canister filters.