We are connected to a rural water system and there is a pressure regulator connected to the home side of the water meter. I purchased a pressure gauge at Lowe's and tested the pressure at my kitchen sink and at the outside entry point of the water line. It appears to be from 60 to 80 psi. (Closer to 60) However, if I have the water on at my kitchen sink and turn on a faucet somewhere else, especially flush a toilet, the pressure will drop to about 20 psi. How can I have that corrected?