The Pentair/Sta-Rite System 2 Mod D.E. Filter's unique design provides two major advantages over traditional-style D.E. filters: its single cartridge style module replaces the more complicated multi-grid assemblies that are difficult to clean and reassemble; and its unique balanced-flow tank design maximizes the use of the module’s surface area to trap more dirt and reduce the frequency of cleaning. This guide shows you how to clean a Sta-Rite System 2 Mod D.E. Filter. As water flows through the D.E. coated folds of this cartridge filter, the folds will become clogged, water will not flow thru the filter as easily, and pressure within the filter will increase. Operationally, with water flow down, you will not be turning you pool water as frequently and your pool decontaminates will start to build up. It's time to clean your filter. As a general rule of thumb, your filter should be clean at least once a month during the summer and every other month if running in the winter.