Filtration foam 30ppi for crystal clear water; for use in the API; Filstar xP. The 30 ppi foam pad is an ideal thickness to filter small waste particles (2nd 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 filtration foam pads simultaneously so as to ensure optimum biological balance. Instructions: Place a foam pad into the bottom filtration compartment, above a 20ppi foam pad.
Fits API XP1, XP2, XP3 and XP4 canister filters.