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 20, 30 and 50 – Large cartridge. 

• 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 45 gallons
• Uses One Large Aqueon Replacement Cartridge and Size 30/50 Specialty Filter Pads