First time grow!!! Flowering now. So what's the best amount of nutes for autoflowers.

Hi
I'm approaching week1 of flowering I'm wondering how much nutrients I need to mix with water without burning my autoflowers.
I'm using plant magic oldtimer soil with grow and bloom, raw additives aswell. I've only used a little grow and Raw B-vitamin through the veg. A couple have took a nasty turn but the rest are growing healthy.
What are my nutrient limits for the first week of flowering as the Raw additives seem to be strong. These are soluble powder and supplement any feeding program.

Feed more if plants are hungry, less if over fed. It's really that simple.

Personally i would only start by adding a bit at a time i.e 1/4 of the stated doseage and see how it goes. To many nutes will inevitably burn