I am trying to resolve a water hammer problem at my in-laws house. The hammer comes only when the pump shuts off and it sounds like a machine gun for a few seconds but quickly fades. The system is comprised of a 40-60 lb jet pump that feeds through a check valve then into to 20 gallon Wellxtrol storage tank that then feeds into the distribution. Unlike my own system, the pressure gauge and switch for this system are mounted on the pump, not on the storage tank. I’ve been able to isolate the problem to the storage tank and I suspect that there is not enough pressure in the bladder. What is the proper method for checking and setting the pressure for the storage tank? Any guidance would be greatly appreciated.