Low water at pump

[Bikerndiver]

I just had a new above ground 18 x 40 x 54 pool installed. The pool is filled to its correct capacity. I'm using a 2 speed 1.5 hp pump and a Hayward Pro Series sand filter. Here is my problem:

+ After running the pump on LOW for an hour (+ or -), the strainer basket just before the pump is virtually empty of water....

+ If I run the pump on HI, the strainer basket is empty of water in a minute or two. The skimmer opening is still full of water.....

+If I remove the skimmer basket up at the skimmer opening, everything works fine on either Hi or Low speed.....

Is my basket at the skimmer not letting enough water through???? What do i do about that????
Thanks!!!