SuperPro DE Grid 15-3/16″ x 18″, FC-9840

The SuperPro FC-9840 is a replacement DE filter grid measuring 15-3/16 inches by 18 inches. It is listed against the Sta-Rite System 3 D.E. filter parts group, which covers the S7D75 and S8D110.

What a grid does

A DE filter works by holding a thin cake of diatomaceous earth on the fabric of each grid. Water passes through the cake, the cake traps the fine dirt, and the grid is simply the frame and fabric that keeps that cake in place. Nothing filters until the grids are intact.

When to replace one

The clearest sign is DE returning to the pool after you charge the filter. That is powder passing through a split in the fabric or an opened seam rather than being held on the surface. Grids also stiffen and clog with age and stop taking a clean coat.

Ordering

This is a single grid in one size. DE tanks take a set, and several sizes exist in this range, so pull the old grid and measure rather than ordering from memory.