Aqueon QuietFlow Power Filters and cartridges were designed with the fish and the aquarist in mind. Our patented designs include unique features to enhance water quality and clarity, increase oxygen levels and lessen noise. Aqueon QuietFlow Power Filters feature four stages of filtration-mechanical, chemical, biological and wet/dry-for the cleanest, clearest, healthiest water. Higher flow rates ensure higher dissolved oxygen content for healthier, more active fish. The internal pump design helps dampen noise, eliminates leaks and starts up automatically after cleaning or power interruptions.