From a quick glance, I worry that your pump is too big for your filter. Hayward rates the filter at a maximum of 50gpm, but their own 1 hp above ground pumps don't get below that until you have 50' of head--long plumbing.
What brand and model of pump is it?

A 1 hp pump on an 8500 gal pool is certainly over-kill, even for an up-rated pump. I have a 1hp 2spd on my pool and it's far larger and STILL my 200# sand filter is barely within spec at full speed.

I suspect you need a smaller pump, or a smaller impeller on you pump, or a bigger filter.