Hi Folks, 1st post, I basically do handyman work for a few folks. One of my clients has had some irrigation problems and I have been going through the system. All is fine now but one area. The sprinkler heads take 15 minutes to start after the pump starts. The water is drawn from a lake. I replaced the check valve, which is partially submerged, and almost at the end of the PVC going into the lake. The supply PVC is probably 12 feet of a 30* uphill run before it gets to the pump. The check valve is also about that far away. Should the check valve be closer? Any other hints to get water pumping faster? Thanks.