Clean & Clear Plus Cartridge Filters Clean & Clear Plus Cartridge Pool Filters have a corrosion-resistant, injection-molded, fiberglass-reinforced, polypropylene filter tank featuring superior strength and reliability. The cartridge assembly uses four, nonwoven, polyester cartridges. There is no need for backwashing. Four-Cartridge Design The Clean & Clear Plus filter’s design provides maximum filter surface area to capture more dirt and solids and stretch out time between cleanings. Plus, we use the most durable materials to extend cartridge life. The Clean & Clear Plus filter delivers commercial-grade performance that keeps pools clean and sparkling, day in and day out. Four Hard-working Cartridges Keep Pool Water Clear Pentair Clean & Clear Plus Cartridge Filters have a large filter area for increased dirt capacity, and if the pressure gauge shows that the system is running at 10 PSI higher than its starting pressure, it is time for a cleaning. Be sure to consult a pool professional before performing maintenance or attempting pool filter cleaning on your own, or call a servicer outright if you're unsure of how to clean a pool filter. Clean & Clear Plus Cartridge Filters Large filter area for increased dirt capacity