Waterway 570-0048-07 Crystal Water D.E. Filter 48 SqFt 96 GPM. Designed for today's most demanding installations, the Crystal Water D.E. Filter sets the standard of performance and features for pool filters. The only D.E. filter on the market with 2 1/2" internal piping, improves flow and reduces system noise when using 2 1/2"or 2" plumbing. With the 2" bottom clean out port, the Crystal Water D.E. Filter will provide years of trouble-free operation and crystal clear, sparkling water.