pressure too high

[Phillbo]

My DE normal pressure is around 12 psi.

[Pool Clown]

If you wanted to check and see if it is the grids, take the grids out and put the filter back together, switch your valves to spa. Start the filter, bleed the air, and note the pressure.

Note: when you do this, you are likely to get a bunch of D.E. back to the pool. Thats why you switched the valves to spa, to keep the mess contained. When the filter is reinstalled, just drain the spa (draw from the spa, and return to the pool), and the filter will catch all the mess.