Description The Fluval Power Filter is designed to keep your aquarium water sparkling clean with five full stages of filtration. The extensive five-stage filter system includes two mechanical, one chemical and two biological filter chambers, while most filters only have one of each type. This filter is designed to trap large and fine debris and remove dangerous toxins all while cultivating good bacteria for a healthy environment for your finned friends. The mechanical filtration is performed by a thick poly/foam that traps debris. During the chemical stage, activated carbon removes toxins from the water. In the final biological stages, a Bio-Screen pad promotes healthy bacterial growth and contributes to fast and effective nitrification. Key Benefits Extensive 5 stage filter helps to produce clean and clear water conditions and a healthy environment for aquarium life to thrive. Provides maximum surface area and optimum dwell times in all stages of the filtration process. Features 2 stage mechanical filtration that effectively traps large and fine debris, reducing harmful ammonia and phosphate build up by removing fish waste, uneaten food, and other organic materials. Activated carbon for chemical filtration to effectively remove dangerous toxins while the Bio-Screen pad provides encourages the growth of good bacteria. The patented refiltration control system lets you slow down the water output, creating a gentle flow to protect delicate fish and plants