The residential water well owner should set the pressure in a bladder tank at 2 pounds per square inch lower than the cut-on pressure for the well pump. A tire pressure gauge placed on the valve at the top of the tank can check the pressure.
Bladder tanks, like tires, sometimes leak air. The installer usually checks the pressure at installation, but owners should check it a minimum of every six months. If the tank pressure is too low, the owner can add more air using a portable air compressor. The pressure increases due to the reduction in air volume in the tank as the well pump fills it with water. Most pumps shut off after increasing the pressure in the tank by 20 pounds per square inch.