Why you need: Compatible with tetra filter medium catches debris and fish waste, absorb heavy metals from water and improve the taste of water, effectively maintain PH balance in water. All medium fish tank filter cartridges protect your pets from muck. Package includes a 12-pack of premium pet fountain replacement fish filters for aquariums. 3-Layer Vertical Filtration: Dual-sided mesh catches debris and fish waste. Whisper pf10 filter Fit for tetra filter cartridges, filter for fish tank replacement for tetra whisper filter Activated carbon absorb heavy metals from water and improve the taste of water.The non-woven fabric captures impurities Replace The Filter Regularly: We recommend that you replace fish tank filters compatible with tetra whisper filter medium and medium tank filter & aquarium filter media fit for tetra medium filter cartridges every 2-4 weeks to maintain water quality. (It depends on the number of fish in fish tank Quick Installation: Turn off and remove the used aqua culture m filter cartridge and flush the cartridge under cool clean water or water filters 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 Perfect Compatibility: This aquarium filter cartridge is compatible with Whisper Bio-Bag External Filter PF10, compatible with Whisper External IQ10 and compatible with Whisper 10i Internal Filter and compatible with TetraFauna ReptoFilter 20 gallons (90 GPH) Why you need: Compatible with tetra filter medium catches debris and fish waste, absorb heavy metals from water and improve the taste of water, effectively maintain PH balance in water. Each set is individually packaged and sealed to maintain high quality 3-Layer Vertical Filtration: Dual-sided mesh catches debris and fish waste. Whisper pf10 fi