I was watering the garden and the water pressure went down to maybe 2 psi on the gauge I tried turning off the well pump 220 breaker for ten seconds and back on. I heard a pffft when it came on and the water pressure went up in a secind to a pretty good 44psi. I think it was a little higher than that when I repressurized the tank a couple months ago. I might need to try that again. Any idea why cycling the power to the pump had such a drastic effect?
Check the pressure switch that cycles your pump on and off, it may be malfunctioning.
So you are using water and the pressure is dropping/low; the pressure switch should sense the pressure drop and kick on the pump, which would fill the tank (compressing the air in the tank) and cause a steady rise in pressure. In theory, when all system components are working correctly, you should never see drastic rise or drop of pressure.
It sounds like maybe the pressure switch did not kick the pump on at the appropriate setpoint. When you shut the system down entirely and the pressure dropped way low, the switch activated and the pump kicked on.
There are other things it could be I guess (like an electrical malfunction or pressure tank problem of some sort).