How to I adjust the pressure in my home water well diaphragm tank?

First of all, the pressure on the tank should read about 30-35 psi with the well pump turned off, all water drained from the system. Take a tire pressure instrument to the top of the tank and take a reading. If it's high, then bleed it off a little at a time. If it's below 30 then add air pressure to read between 30 and 35.

Wait a minute. The pressure at the "top" of the tank should read 2# below the cut in pressure point. So, if your pump is cutting in at 35 pounds, then you would set the tank pressure to 33#. However, if the cut in point is 40 pounds, then you would set the tank at 38#. QTech is correct in saying this should be done with the system off and the tank drained.

TJ, is that what you are after, or do you want to raise the water pressure on your system?

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Originally Posted by jlisenbe

Wait a minute. The pressure at the "top" of the tank should read 2# below the cutin pressure point. So, if your pump is cutting in at 35 pounds, then you would set the tank pressure to 33#. However, if the cutin point is 40 pounds, then you would set the tank at 38#. QTech is correct in saying this should be done with the system off and the tank drained.

TJ, is that what you are after, or do you want to raise the water pressure on your system?

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Actually, I do want to raise the pressure on my system.

Do to that, go here:

How to adjust water pump pressure, pump cut-on pressure and pump cut-off pressure - private pump and well system do-it-yourself repairs

However, do remember to set the pressure correctly at the top of the tank.

I wouldn't set the cutoff at anything above sixty... makes life kind of hard on the pump. Mine is presently 40-58.

I have a 20 gal tank. What should my air preasure be?

Same as anyone else's. Turn off the system, drain it through a nearby faucet to pressure of zero. Set the pressure at the top to 2# below the cut in pressure. For example, if your system cuts on at 35#, then set the pressure to 33#.