140' well, water 25' from surface, 6" plastic casing, sears deep well jet pump and jet. i have 1-1 1/4" pipe & 1-1" pipe going into the well. i fill pump up for prime but it will not pump. someone told me i need a pressure tank and 28 lbs of pressure to operate the jet at the bottom of the well. if this is true how does the pressure tank hook into the pipe? i have a 30/50 switch. will a 300 gal open top tank work for the 28 lb. pressure requirement?[?]