The filter grid assembly is where the DE is actually located and the dirt is trapped inside the filter. It consists of 7 large grids and a small grid held together by two tie rods going through the center along with a top manifold, an internal bleed assembly, a filter template, and a holding wheel. The Pentair FNS Plus DE Filters come in 3 different sizes. The corresponding part numbers for the filter grid assemblies are as follows:
- 59023500 is for the 36 sq filter, which comes with 7 large 18" and a small 18" grid.
- 59023400 is for the 48 sq ft filter, which comes with 7 large 24" grids and a small 24" grid.
- 59023300 is for the 60 sq ft filter, which comes with 7 large 30" grids and a single small 30" grid.