When & What Nutes To Add

My friends plants have a few sets of leaves, he says the foliage growth has taken off in the past week or two. He thinks they are just beginning veg stage. He has the following nutes; Vitamin b1, Jungle green 17-15-17, Royal black 0-0-1, And royal gold 0-1-0. When and what and how much nutes should he use??? Thanks guys please respond ASAP as he is trying to keep the plants short and he thinks it needs nutes now??

Let it grow on just balanced pH water for 3 weeks then starting adding light nutes, and work your way up. Just do 1/3 less then what the back of the directions say.