6 Pack Filter Cartridge for Tetra Whisper Bio-Bag Filters, Large Replacement Filter Cartridges for Aquariums Compatible with Tetra Whisper Filters 20i,40i/IQ20,30,45,60/PF20,30,40,60 and ReptoFilter Item Description -?Filter Cartridge for Tetra Whisper?6pcs Large Remplacement Filter Cartridges, Unit Size: 5.1 * 6.7 inches. This aquarium filter cartridge is compatible with Whisper Bio-Bag External Filter PF20, 30, 40, 60/ Whisper External IQ20, 30, 45, 60/Whisper 20i 40i Internal Filter and TetraFauna ReptoFilter 50 gallons (125 GPH). -?Four-Stage Filtration?The filter is made of dense dual-sided mesh, Better thickness provides better filtration, Ultra-Activated carbon instead of ordinary carbon and also add processed zeolite, which can effectively filter and absorb impurities in the water to keep the clean water source and provide the healthy growth environment for fish. -?Efficacy of Zeolite?It can adsorb ammonia, heavy metals and other harmful components in the water. Effectively balance the PH value of the water body to achieve a stable water state. Zeolite can improve the fertilization efficiency of aquatic plants, make your aquatic plants, nitrifying bacteria grow faster, live more comfortable and more health. -?Quick Installation?Turn off and remove the used cartridge and flush the new cartridge under cool clean water or water of aquarium to remove dust. After rinsing, insert the cartridge into the flushing chamber and make sure the filter cartridge fits completely into the chamber. -?Professional After-sales service?TIPS: We recommend that you replace the filters every 2-4 weeks to maintain water quality.(It depends on the number of fish in fish tank). We are professional in the field of Aquarium Filter Cartridges, if you have any problem, please feel free to contact us. Payment We accept payment only through PAYPAL Shipping We ship products worldwide through standard express courier service, it will reach within 7 to 10 days to abroad buyers, we ship the product after recieved clear payment and give full information about shipment to the buyer Return We accept product return within 7 to 21 days from delivery date but product should be in original position and not in damaged condition,the return shipping charges will be buyer responsibility