When to start fertilizing the soil Gold Label Special Mix?

My friend bought such soil, because there was no BioBizz in the store. Now we are wondering when to give the first dose of BioBizz fertilizer (Grow/Bloom). Photoperiodic plants had 14 days of vegetation. Now they are at the age of 4 weeks. When to start fertilizing and in what dosage? (1/4, 1/2, or full dose) In the instructions they give 3-6 weeks without fertilizing.

Pics are helpful

They were unattended for 8 days and it got a bit of a mess. Soon, part of the leaves will be cut and a grid will be placed to level the level.
6 x Jack Herer GHS.
(container 45l)

I wouldn’t change a thing for a couple more weeks