I have a 2hp pump connected to my 2 inch well which is about 22ft down. My pressure keeps going up and down, I'm thinking lack of water. I have plenty of water in the point but not sure it can "refresh" itself fast enough for a 2hp pump. I have a extra 1/2 hp pump, could I hook that up to my 2 inch well with a 1 1/4 output or is it to small for that size well.to run a sprinking system? 7 zones, 5 heads per zone.