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 youGÇÖll enjoy low maintenance for as long as you own your filter! It's 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. It's a Chemical Filter - Ultra-Activated-« carbon removes odors and discoloration better than competing cartridges. It's 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.