LED indicator light flashes when liquid 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 50 gallons Uses One Large Aqueon Replacement Cartridge and Size 30/50 Specialty Filter Pads
