Hi. I am replacing my galvanized water lines with cooper in a two story house with a basement. I have the main coming in at 3/4 and will run the supplies at 1". My question is for the first floor supply lines should I knock them down to 3/4 then branch to 1/2" or should I branch of the 1" with 1/2" to the fixtures? The runs are about 10-15 feet from the main supply. I have about 35 psi. Thanks