I have a submersible well pump and a diaphragm type pressure tank that was replaced 8 years ago. It seemed to be cycling more than normal lately so I recharged it the other day to 38lbs (40-60 switch). It now holds steady at 60psi when not in use. The first draw down seems to take the normal amount of time but once it hits 50psi the pressure drops almost instantly to 40psi and then kicks on the pump which builds up pressure to 60 psi in 15 seconds. It then cycles on and off every 50 seconds. Starts at 60 goes to 50 then drops to 40 almost instantly building back to 60 in 15 seconds. Continues to do this while water is in use. Once water use stops charges to 60 and holds pressure. I did drain water from tank and turned off supply from tank to house before charging. Any thoughts out there? mtb

You probably have a restriction in the discharge line between the pump and the pressure tank, usually right near the pressure tank to affect the pressure switch. The usual culprit is the tank manifold where it threads into the tank ell and becomes clotted with rust as a result of electrolysis. Removing, cleaning, and reinstalling will correct it but is most always short-term once electrolysis begins. The best solution is to replace the tank with a tank using a stainless steel ell (Well-X-Trol, 7 yr warranty) and a stainless steel manifold tee.