You need to precharge the tank with the appropriate amount of air. This should be ~2 pounds LESS than the turn-on pressure of the pump control. SO if it is set to 30/50, it would be set to 28#. tO do this, you need to shut off the pump, open a valve and let the water run until it stops leave it open until you finish, then pump up the tank (or bleed off some air). SHut the valve and and turn on the pump and see what happens.