You should add full amount after a teardown and 80& after a backwash. Otherwise there will be bare patches that won't filter.I got things up and running with half DE (about 1.8lb of the recommended 3.7lb). I think I may have mixed it too thin. I added the powder to about 2/3 of a big Home Depot utility bucket. Will this affect how it coats my grids?
Here's my starting pressure of about 15psi.
Going to let it run for a bit and then do my CYA test. Then I'll make a run to ACE to see what their bleach situation looks like.
It the DE that filters, not the grids. Picture a layer of kitchen sponge supported on a bed of chicken wire. Water has to pass through the holes in the sponges. Now shrink it to microscopic size. That's a DE filter grid. Without a layer of sponge, the water will just pour through the chicken wire.