I had 4 gallons on an open pipe.. no spray nozzle.. I had purchased a spray nozzle that was “2.5” gallons but got less then a gallon per minute.. I couldn’t get the shampoo out of my hair.. and so I went back to an older nozzle.. I just was trying to figure out if I was getting enough water or water pressure..
who ever did my plumbing was an idiot with a brainstorm.. its not exactly done by pros.. there are a ton of twists and turns.. and for example with the exception of my wash machine faucets, there is only one turn off in the whole house..
I have very little flow to my bathroom sink and toilet.. but the shower seems to get much more water.. I would bet that my cold water to my sink or toilet is less then a gallon per minute.. yet its within feet of the shower/bathtub..