Compare Quick view Hayward HAYWARD | FILTER DE 72 SQFT NO VALVE PRO GRID | DE7220 MSRP: Was: Now: $1,303.32 HAYWARD | FILTER DE 72 SQFT NO VALVE PRO GRID | DE7220 Pro-Grid™ Vertical Grid ITEM # PROGRIDVG Description Diatomaceous earth is a porous powder with microscopic openingsthat when magnified look like tiny...