Featured is a LED filter cartridge change indicator light that flashes when the cartridge becomes clogged with debris， providing a reminder that it's time to replace the cartridge. A great benefit of the Aqueon QuietFlow filters is the internal pump design that helps dampen noise， eliminates leaks and is self-priming， meaning it starts up automatically after cleaning or power interruptions. Higher flow rates also ensure a higher dissolved oxygen content for healthier， more active fish. There are five total stages of filtration–mechanical， chemical， biological and an additional specialty pad–for the cleanest， clearest， healthiest water. Stage 1 – Dense floss removes particles and debris. Stage 2 – Activated carbon removes toxins， odors and discoloration. Stage 3 – Patented Bio-Holster provides surface area for beneficial bacteria that remove toxic ammonia and nitrites. Stage 4 – Bio-Media grid supports additional beneficial bacteria establishment while adding more oxygen. It also reduces splashing making the return exceptionally quiet. Stage 5 – Specialty filter pad option for additional carbon， ammonia reducer or phosphate remover. All filters use Aqueon Replacement Filter Cartridges and Aqueon Specialty Filter Pads. QuietFlow LED Pro 10 – Medium cartridge. QuietFlow LED Pro 20， 30 and 50 – Large cartridge. QuietFlow LED Pro 75 – two Large cartridges. Change filter cartridge every 4 weeks for best results.

• LED indicator light flashes when water cannot pass through the cartridge， generally indicating it's time to change the cartridge
• Self-priming filter pump will auto-start initially or restart if power is interrupted and restored
• Provides mechanical， chemical， biological and optional， additional specialty pad filtration
• High flow rates for optimal dissolved oxygen content to promote healthier， more active fish
• Internal pump design helps dampen noise and eliminate leaks with self-priming feature
• Do not clean Bioholster when replacing the cartridge as it contains beneficial biological bacteria
• Fits fresh or saltwater aquarium size up to 30 gallons
• Uses One Large Aqueon Replacement Cartridge and Size 20/75 Specialty Filter Pads