We strive for improvement not prefection.
If you are having wild swings in your Ph there is something else wrong.
Don't get hung up on maintaining an exact #, you want some fluctuation within the range, look at what Ph your nutes get absorbed (and locked out for that mater).
Constantly adjusting your Ph stress out you and your plant.
I Ph when I add to or change the rez, other than that i don't adjust.