Last year around August, we had to do some work on our mater bathroom so we started taking showers upstairs in the guest bath. When we first started taking showers up there, the water pressure was awesome but after about 4 months the water pressure was pretty weak. Well, we finished the master bath and when we started taking showers down there again, the water pressure was awesome and now its weak again. Does anyone have a suggestion as to why this would be? BTW, the pressure in the upstairs bath is still pretty weak and the pressure at the hose spigots and sinks is fine.