Installed a 3/4 hp 10gpm submersible in river to irragate lawn open discharge I am using craftsman extra large sprinklers 8500sq ft reccomends running between 30 and 50 psi. My question is I normally run 2 sprinklers tried three but will not run third one very well, I tried one sprinkler and it really threw the water, soaked the ground in no time covered 120 ft ciircle. I don't know if it is building up to much pressure for the pump if so will it hurt pump how can I tell when it is to much pressure for the pump or not. How can I tell when I am running the right pressure or not or is there a way to tell.