The Tetra Power Filter 10 uses a 3-stage filtration process to create clean, healthy water for your fish. This dependable filter features ready-to-use cartridges that are easy to change, so youGll enjoy low maintenance for as long as you own your filter! Its a Mechanical Filter The filter pulls water from the aquarium and pushes it through the filter cartridge where the dense, dual-sided mesh catches debris and waste. Its a Chemical Filter Ultra-Activated- carbon removes odors and discoloration better than competing cartridges. Its a Biological Filter Bio-Foam- creates a large 3-dimensional area for cultivating aerobic bacteria, which eliminate toxic ammonia and nitrites. No moving parts mean long-term reliability.