Thought I'd ask a questions that's been bugging me for 6 months:
I have a Quad DE 100 filter (see rest of specs below) and have just cleaned it for the beginning of the season (and because the landscape work is finished -- so the daily shower with dirt is over). I figured it would be pretty bad, so I did not backwash it, but rather drained it down, opened it up, and cleaned the grids with a hose. I typically will open the drain-plug at the bottom, disconnect the in/out screw fittings (to the slide valve) and take the whole thing out for a good cleaning.
When I look at the bottom of the filter case, there's 3-4 inches of DE there. After the top half inch or so, it's pure white. It's never been used, re-curculated, on grids, etc. It calls for 10 pounds on full re-charge - so I'm putting the correct amount in....
Also, hard to say if any DE is on the grids, but I assume it'sjust supposed to be a thin layer that can't be seen (with all the dirt on the grids).
Pool looks clean enough, so must be working, but ...??? Should I be putting less DE in? Is this just normal for a bunch to go to the bottom while the grids are being coated? If I decide to backwash next time, I am afraid that this cake of DE at the bottom would remain there.
On a side-note: the filter breaks down quite well and the grids hose off easily.