Replacement foam for biomaster

• The Pre-filter Foam Set 30 ppi for the BioMaster 250, 350, 600, 850 and BioMaster Thermo 250, 350, 600, 850 includes 4 coarse replacement filter foams
• Customize your choice of filter foams to meet the needs of your aquarium
• Timing to replace the pre-filter foam set varies upon aquarium size and the number of fish and plants