26,500 gallon pool, Hayward sand filter
TC 6
PH 7.8
TA 90
CYA 45
BO 45

I backwashed my filter and added 2 cups of DE to my sand filter, 1/4 cup to a gallon of water at a time. My pressure is up from 1/2# to 3/4#; it jumps a little. I did not want to put more than 2 cups in even though I did not get a full 1# of pressure increase. I will watch the pressure tomorrow.

Now my DE Pool School question. When should I add more? Your page did not inform me of future use.

You would add more whenever you backwash. It'll backwash out with the debris.

Makes a nice snow globe in the sight glass!