Carl,
Do DE and sand filters have a part number located on the actual filter? I need to find out. The previous homeowner left no information regarding filters.

I found out that you should add 80 percent of the original new dose of DE to your filter after backwash. I backwashed this weekend and didn't add DE because I didn't know i had too. So now i have backwash then remove the filter and clean it with a hose then add more DE to the closest skimmer (just add powdered scoops).