Aqueon Phosphate Remover for QuietFlow Specialty Filter Pads provide additional filtration to remove specific contaminants from your aquarium. The phosphate pads provide an additional stage of mechanical filtration by helping to remove excess phosphate that contribute to algae growth while trapping excess waste, food and other organic debris. Pre-cut for quick and easy installation. Traps excess waste, food and other organic debris Fits the Quiet Flow LED Pro 30/50 Pre-cut for easy installation Replace pad every 2-3 weeks for optimal filtration.