I drilled a 2" hole in my basement, dug an 80' foot trench to a pond abutting our property, and connected 80' of 2" inch pvc pipe, with minimal joints, to a 1 hp jet pump in basement, with a foot valve at the end of the pvc pipe, which is in the pond. I prime the pvc pipe, but when I turn The pump on, no water comes through the pipe. Elevation over the 80 feet is minimal, maximum 2 feet. All joints are air tight, no leaks. Should I put a check valve befor the foot valve?