It sounds like a well problem, like pumping it down too far. A potential problem with the use of a large pressure tank; they cause more water to be taken out of the well all at once as opposed to a smaller amount followed by none and then being repeated.
Increased pressure such as 40/60 when 30/50 will work just fine except for power washing yer butt... causes more water to be used. That causes more water to be removed from the well all at once. If the well hasn't recovered by the time the pump comes on again, the well is drawn down farther and water quality can suffer.
Water conservation may be a good idea. Did you have this problem before replacement of the pump?