Can anyone tell me how you know when all of the DE is backwashed off the filter so you know when to stop and refill with DE. Judging by what comes out I know that all the dirty DE isn't being wsahed out. This is my problem because I guess on how much to replace. The manual says replace withg what you started witht but if did that the filter would clog up? Do you just go by the color of the water in the glass, time of backwash, or go buy how clean it runs out of the end of backwash hose? Thanx.

Jandy DE 48 Filter
IG Plaster 23000