I am helping a friend that recently purchased a cabin get his water system online. He has an existing 3/4 hp Craftsman shallow well jet pump that was mated to an 85 gallon Craftsman captive air tank (bladder type) that is drawing water from a well that is about 12-15 feet lower than the tank/pump.

We determined that the existing tank bladder was leaking, so we replaced it with an 85 gallon Pro-Source Plus (#PSP85-T52) that was supposed to be 'pre-charged' to 40psi.

The label inside of the lid of the pressure switch attached to the Craftsman pump indicates it is a 40/60 switch.

Got it all hooked up and fired it up. Filled up fine and it shut off at around 46 psi as measured at the pump from a gauge installed in the prime port on the pump housing. I also installed a second pressure gauge near the tank and they read within 1 psi of each other. Ran some water from a hose bib and nearest I could tell (since I was running back and forth from the watching the water flow to the pump/tank location) the pump came back on somewhere between 30-35 psi and then shut off again around 46 psi.

Basically, it seems to work, but I want to adjust it to spec to get proper performance and durability.

I see that pressure switches are sold 'pre-set' to various settings (20/40, 30/50 and 40/60)

1) Does this mean that if I want to set this system at 30/50, I should get a different pressure switch or can I just adjust the existing switch to the pressure I want to run it at?

2) If I want to run at 30/50, should I empty the water from the tank (not a problem) and adjust the air pressure in the tank first (to 28 psi) before adjusting the switch settings?

3) Since I can't find an actual step-by-step for adjusting the switch, should I just turn the cut-off pressure adjusting nut a half turn tighter and keep cycling the system (open the hose bib and let it drawdown until it cuts back on) until I get it to the pressure reading I want, or can I just turn the nut in and let it (assuming it will) cycle on & off repeatedly as I tighten the adjusting nut until I get the desired pressure reading?

4) Same basic question as #3, except for the cut-on pressure adjustment.

Thanks in advance!