i have a 140 liter tank under plants so I fill it, all my nutrients go by the 10 liter, so I ad 14x each one of the 5 nuts stiring inbetween, then as the tank gets half empty I put in 7 times the 4 nutrients for rest of flower. I then look at ph on meter and ec, if within my tolorences just leave it, usualy is ph 5.8-6.2 and ec 2.4-2.8