Hayward HCF7030C HCF Series 700 SqFt Cartridge Filter. The Dual Quad-Cluster commercial HCF7030C cartridge filter system features a massive 700sq ft. of filter area providing heavy-duty, dirt-holding capacity and extra-long filter cycles. It will reduce operation costs and enhance the eco-friendliness of the facility by saving thousands of gallons of carefully-balanced, heated pool water per month through the elimination of backwashing.