When my well starts, it often -- but not always -- starts with a jolt that shakes all of the supply piping in the basement. I have a submerged pump feeding thru a check valve to a tee. One leg of the tee is runs to the load (the water softener, and then the rest of the house), while the other leg of the tee contains the pressure switch, a pressure gauge, a safety blow-off, and the pressure tank. All components are less than 2 years old. Here's a pic of the setup:

http://www.antrobus.us/watersoftener/20050326b.jpg

http://www.antrobus.us/watersoftener/20050326c.jpg

Initially, I took the listed 40 - 60 psi range of the pressure switch at face-value, and set my tank's bladder (when drained) at 38 psi. This resulted in hard starts, and my theory was that the pressure must be too high, causing the system to run completely dry for a fraction of a second before the well pump kicks on (if the bladder pressure is higher than the cut-in pressure, it will push all of the water out of the tank before the well cuts in). This theory seemed to be confirmed by the fact that my first pressure switch, which was of the variety that would reset any time it lost pressure, was constantly resetting itself. I replaced that switch with another 40 - 60 psi one lacking that "safety feature", but never got rid of the hard starts.

My pressure gauge seems to stick a bit (the needle jumps by as much as 10psi when water is flowing and I flick it with my finger), so it's tough to get an exact reading on my cut-in and cut-out pressures, but as near as I can figure it, my cut-in pressure is 36psi. So, I drained the system dry, set the pressure in the bladder to 34psi, and figured that should do it. When I tested the system after doing this, it seemed much better the first time. Eventually, however, the problem came back! I believe that my problem may be due to a pressure switch that cuts on/off at inconsistent pressures. Does anyone have any experience with this? Am I correct in my theory that I should err on the low side, if anything, when setting the pressure in the tank? What if I set the tank pressure as low as 28 or 30 psi when the system is drained? I'm not sure how much "headroom" the tank has, to deal with a situation where the bladder pressure is set too low.

Thanks in advance,
Rick