KISS. (keep it simple stupid)
hydro is simple. don't overcomplicate it. start on a low ppm and monitor your solution to see what your plant is using.
plants will only use what they need from the solution and they put the rest back.
so if the ppms are dropping your plant is using more nutrient than water so you can feed stronger.
if the ppms are staying the same then your plant is using equal amounts of nutrient and water and the feed strength is spot on.
if the ppm's are going up then your feed strength is too strong and you are in danger of doing damage.