For a better shower, replace shower head (likely 1.8 gpm) with 2.5 gpm showerhead. "low flow" 1.8 gpm shower heads have been the norm since 1992. for a better shower, I tried replacing the pressure reducing valve at the hose end with a 'high flow' one, replaced the water pump with a 5.0 gpm AquaJet pump, all to no avail. Finally replaced the shower head with a 2.5 gpm unit and problem solved.