distance from skimmer to pump

[marc_]

I'm currently having an inground pool installed, I wanted to have the pump and filter installed inside my shed (to be built soon). Problem is the installer tells me the distance is too far and will cause problems with the pump. I don't understand what's the difference with the distance, once the hose is primed does it matter how far it is. Would a check valve be necessary or help?

I'm really new to this so here's the info I can provide that I know.

skimmer to shed is 60 feet in line with slight bend
pool is 14x28 approx 45000 litres or 12000 us gallons
pump is hayward 1hp
hose is 1 1/2 inch

Thanks