Available in top-mount and side-mount configuration this series high-rate sand filters use the latest technology in sand filtration with engineering refinement that have improved tank hydrolic flow and dirt-loading capability. The Cristal-Flo sand filter also provides more plumbing options for installer. The T-BP series sand filters are designed for residential in-ground or above-ground swimming pools requiring turnover through 59,000 gallons, at flow rates up to 20 GPM for 8 to 10 hours. Permanent media high rate sand filters in 15″, 17″, 20″, 24″ and 30″ diameter model accommodate large and small pools, offering the best combination of economy. performance, durability and ease of mentainance. Corrosion-resistand one-piece extra-thick molded polyethylene tank assures long service life. Top-mounted, corrosion-resistant multiport selector valve included. Also includes a convenient tank winterizing drain and continuous air relief system.