Backwash Question with new pump

[PoolDoc]

Pool guys, like me, NEVER do any thing like that. No. Never.

Well, at least not any times I'm going to tell anyone about . . . .

[robbym70]

Yup...hoses were reversed.

Missing my old pump/motor...which was a two speed 1/ 1/2 Hp set up.

New one is pumping away happily but is it normal for the suction on the pump to decrease almost down to nil after pushing around the hand held vacuum? That's happened both times with the new pump but it reverts back to correct pressure after backwashing. Second season in...still learning.

[PoolDoc]

Yep. When the filter gets dirty, the pressure on the filter goes UP, and the flow through the pump (and vac head) goes DOWN.