These unique cartridges were designed to ensure even distribution of carbon throughout for more thorough filtration and longer cartridge life. 

Features:

• High quality activated carbon keeps water clean
• Align cartridge bottom key slot for an accurate fit inside the filter
• Rinse under water to remove carbon dust before replacing
• For optimal performance, change approximately every 4 to 6 weeks
• Do not clean Bioholster when replacing the cartridge as it contains beneficial biological bacteria