Ghost Train Haze + Holy Grail OG Feminized from NOS

does your fertilizer need magnesium or sulfur? if also in soil must consider what comes in the soil. So, it's a matter of a well-balanced diet and not add a pinch of this one week and a pinch of that next week. soil is often amended with gypsum and garden lime among other things. This is more of a guessing game, but a little trial and error gets you there. If in soilless/hydro context, then you'll want 50-80ppm of Mg and 100ppm or even a bit more of S. This is less of a guessing game but still need some trial and error to get you there.

This summer i going to make superliving soil and epsom salt will be one of the ingredients. but there is no easy answer to your question. It all depends on the growing technique what you choose. When you using liquid fertilizers, add a liquid calmag, I think it will be better. When you choose epsome salt, buy it in pharmacy, not in drugstore.

I don't but I'm on synthetic. I use calmag or if I don't want calcium I go with botanicare sweet. That's a good source of magnesium and sulfur. Best option after week 5