Clarification for adding DE to a sand filter

[wireform]

NOT THE POOL IN SIGNATURE

Added DE to the sand filter today as per TFP 1 psi instructions. Water now looks like glass now but here is my dilemma. I just realized the instructions say to mix with water and pour into skimmer. I poured it one cup at a time into skimmer slowly but in its powder form constantly monitoring the gauge till it reached the 1 psi increase. Four hours later I had to backwash since it surpassed the 25% psi increase.
Here are my questions:
A) I know it works but do I have to mix it with water prior to pouring it into skimmer.It took 8 cups to reach the 1 psi.
B) Is the psi increase inclusive or exclusive of the 25% psi increase for backwashing ?
C) Do I add it again over and over or is this with limits.

Thanks in advance, Allan

 

[tim5055]

A) IUt's probably better to mix with water first, but as you proved if you add it slowly to the skimmer it still works

B) The difference is probably inconsequential

C) You can do it as often as you like, but as you saw it can load up the filter quickly. Don't add DE and go on a week vacation....