Great questions SteelToe. If you look at the spec sheets of the blue lab it can get into more details on what it can do so I will keep it in plain language for others to understand.
I set the doser (for PH only). For which way I want it to dose up or down and set my parameters, I have it set to drift between 5.8 and 6.1. It takes measurements every 30 minutes (can be set to whatever you want for measuring)
I used to take my measurements with a pen every morning and evening but with travel I got the doser and it is a lifesaver. Most deficiencies in hydro begin with PH issues.
I additionally have two bluelab EC/PPM meters. One for the Rez which measures the current nute numbers that are different every week dependent on what week of growth they are in. The other meter I have set up in my filler Rez to measure what I’m putting into the Rez so I will know what EC it should Be at after topping off during the week. I change roughly once every 7-10 days again according to the week it’s in or my numbers aren’t performing the way I like them too. Additionally, Bluelabs can be set to reed at a EC or PPM lvls just set it and read it. Easy to use.
Old pic but you get the idea.