I use the meters as a set KNOWN point.
If the plant has a leaf tip burn of 1/32 I add till I get a 1/8 in burn. NOW noting the ppm and ph levels , just change as needed.
The next crop is x ppm and ph levels.
Keep track of the input ph and ppm and ajust levels to meet the set point.
It usualy takes 3 days to see what the plant likes.
AS ALWAYS IF THINGS TURN TO SHIT ,,,,,, FLUSH.
Always clean your meters and calibrate them:smokin: I have only used that method for a few decades, and it still works. :thumbsup: