My system is a deep well submersible (150 ft), 1 hp pump, bladder tank, pressure switch (40-60 with one adjustment spring) and typical residential plumbing. My tank, filter and pressure switch are in a mechanical room in the basement. I have changed the pressure switch twice. I have changed the filter and have checked the precharge on the bladder. When a draw down occurs the pressure goes to 20 or below before the contact close then the pressure goes to 85-95 before the contacts open. This happened also with my pumptrol switch which I got so out of adjustment tinkering with it that my only recourse was to change it out. I tried to adjust the new switch with the one adjustment but only moved it one turn to see what changed. Nothing changed so I moved it back. I am at a loss as to what may be causing this. Welcome any advice. Thanks.