Experiencing low water pressure has slowed in recent weeks to a trickle. "Clean" gray sandy sediment found in a bathtub and toilet tanks and in the filter. Changed filter. Less sand. Pressure still slow.
While you are at it , you might as well try to get rid of junk in the pressure tank and piping. Use the drain valve at the base of the pressure tank to try to push out some sediment. Turn off the pump. Drain the water. Look at how much crap comes out. Turn on the pump, and repeat as long as you see stuff coming out.
On your pressure switch, if you want to try to save it, turn the differential nut CCW. That is the nut on the small spring. The small spring will usually be almost loose. So reduce the differential to 20 psi.
Then change the range nut (on the big spring) to change both the cut-in and cut-out together. 3.5 turns CW is about 10 psi higher. CCW lowers both pressures.
If you cannot adjust the old switch as you want, replace the pressure switch. I have mine set to 38/58 on purpose. I forget whether I started with a 30/50, or a 40/60. Turn the nut on the big spring CW to raise both the cut-in and cut-out together. Expect the differential to be already set to 20 psi on a new switch.
