We just replaced our pressure tank, check valve etc. The problem is that the gauge drops below the 30/50 and then eventually drops to 0 meaning we have total loss of water pressure. We checked the pressure in the tank. Its' at 28% which is the correct amount. We tried adjusting the pressure gauge and it did not help either. In fact we had to shut the pressure gauge off as it was allowing water to pump up past 60psi.
We are at a loss on this one. Also, we replaced the pump in May of this year. We do have iron in our water. Not sure what else to do with this one.