Waterway Crystal Water 570-0425-07 425 SqFt Cartridge Filter 150 gpm. Combining high tech features and an easy to service design, the Crystal Water Cartridge Filter is ideal for new and replacement installations. The only cartridge filter on the market with 2 1/2" internal piping, improves flow and reduces system noise when using 2 1/2", 2" or 1 1/2" plumbing. Using four cartridge elements, the Crystal Water Cartridge Filter offers a superior choice for easy maintenance and crystal clear, clean water.