Gordy, my logic tells me you might be right......other's experience seems to indicate we're both wrong. Anyway, here's my thought:

Sand supposedly filters down to 60 microns meaning anything smaller can get thru.

DE supposedly filters down to 2 microns...that would make me think that DE granules are smaller than 60 microns. If they weren't, I don't see how they could capture 2 micron particles.

So, if that thinking is correct, some could work there way thru the sand...particularly if there was not enough sand in the filter or possibly if the filter was pretty small.

So, if DE particles are smaller than 60 microns, Gordy and I might have a point. How big are they, DE folks?