A Cycle Sensor or a Pumptec would keep you from having to go down and reset the Low pressure cut off switch but, now you just have to wait for 20 or 30 minutes for the well to recoup and the Cycle Sensor or Pumptec to automatically restart the pump.
With those two tanks you would have about 40 gallons of water to use before the pump comes on, IF the tanks were full when you started showers. The problem is that you never know, and Murphy usually makes sure, that your tanks are almost empty, like at 38 PSI when you start showers. Then not only does the pump have to make all the water for the showers but, it is trying to refill the tanks at the same time.
With a pipe coming straight off the well head and a 5 gallon bucket, you can tell how much water the well will produce before it runs dry. I am afraid what you are going to need is a cistern set up. With a 1,000 gallon cistern, even if the well is only making 1 GPM, you can let the pump run at 1 GPM all night and day to keep the cistern full. Then you use a booster pump in the cistern that connects to your two pressure tanks and supplies water to the house.
Even a well that only makes 1 GPM, will supply 1440 gallons per day if you have a cistern to store it in. You can probably supply 2 or 3 houses with that much water, you just have to store it in a cistern so you can use it at 5 or 10 GPM for short periods when needed.
I say the well is going 'dry'; the water is falling to the inlet of the pump and the the pump sucks air and the pressure falls and the safety cut off type switch shuts off the pump as designed. Start water conservation by spreading out water uses.
I say the air volume/pressure in those tanks should be checked and adjusted to be 1-2 psi less than the cut-in switch setting done by draining the water from the tanks. There should also be 20 psi differential between cut-in and out. Low air volume/pressure will cause shorter cycling of the pump and premature tank failure while wearing out the motor and increasing the electric bill.
IMO the plumber is correct in wanting to use less water by decreasing the pressure settings. I don't agree with two pressure tanks that require more water to be drawn from the well each time the pump runs. And with higher pressure switch settings, that causes the house to use more water (the gpm rises) all while you have a low producing well. It's not the setup I'd use for myself or a customer with a low producing well. And the compressed air in the tank(s) produce the power to move water when the pump is off, so if the volume/pressure is wrong in the tanks, your pressure fluctuation is more noticeable and the average water pressure will be lower than if the system is set up correctly. And when that happens, guys raise the water pressure and make things worse and use more water. Isn't that what has happened?
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