Thanks for the help. Then I assume your DE layer sits on top of the regular sand as a sort of a "skimmer sock" for your sand. Kinda makes sense if you think through the flow.

Reason I'm interested is we have a new sand filter and it really sucks compared to our old DE filter. The wife bought it when the pool guys came out for the winterizing of our pool last year. They told her our old DE filters were bad and the replacement cost as identical to a new sand filter. Having checked/cleaned my DE screens right before I left for deployment two month's prior to the pool guys showing up.....they got her/us good! I'm hoping a nice DE layer will make the filter, filter better than it currently does.