You have a slight water leak somewhere. My pump did this for a year until I found the leak. Check your bath room toilet for leaking first. My leak turned out to be a connection inside a wall of the bathroom. Had to peel a wall back to fix it. I would not recommend that you leave the pump 'on' when you are not using water because you may leave and then have a more large leak and water everywhere when you return. Your lines should stay pressurized, even with the pump off if you have nothing that is 'bleeding' the pressure off.
2013 Forest River Salem Hemisphere SBT312QBUD
2001 CrewCab F-250 7.3 PowerStroke Diesel
SuperChip, BTS transmission, 6.0 Trans Cooler