From all the reading I've done, it appears that adding a little DE to my sand filter will greatly reduce the smaller particulate matter. For my pool, so far, this is really only an issue at night when the light is on. (Dear daughter won't get in at night with all the "yuck" even though she'll swim in the same water in the daytime. )
I've also read the DE is considered a carcinogen. I backwash out to the yard, instead of into the sewer. Would a lawnmower blow the washed out DE around, or would it tend to sink into the ground. This is especially an issue for DW, since she gets quite paranoid about carcinogens. Do I just forget the whole thing?