google up estimative index (EI)
tom barr made up that system of fertilization . In a nut shell you dose dry ferts thru the week and rely on massive water changes over the weekend.
I used this for a long while but now premixed all the ferts with distilled water in child safe dropper bottles after my son started walking around.
didn't want to find my son messing with all the chems if he ever managed to find em.
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