I have a well with an in ground pump that turns on and off respectively when system water pressure is between 29 and 50 PSI. There is a 20 total gallon accumulator at the input to the system from the well. It is my belief that the bladder in the tank should be pressurized to 2 lbs above pump turn on pressure when the pump is turned off and the water system bled down to zero pressure. My system was performing at what appeared to be greatly reduced tank capacity. That is when a faucet was turned on the pressure dropped uniformly from 50 to 40 PSI and then almost instantaneously dropped from 40 to 30 at which point the pump turned on. Upon checking the bladder pressure with a tire gauge with system water pressure at zero I found the bladder pressure at approximately 40 PSI. After bleeding the Bladder down to 32 PSI the system performed as I expected it to perform. Unfortunately after a few weeks of use the same symptoms reppeared. A check revealed that once more the badder sits at approximately 40 PSI. After bleeding it down a second time it once more operates correctly. (Note that when bleeding it down to 32 PSI the air coming out felt dry and not wet.) Can someone tell me what is going on?