AsNoriuanswered grow question 2 years ago yes, i was sprinkling great white before putting seed in . You can use great white at any time either mixed into water or just sprikled on top lair of medium and watered after. Just stop all fans, very dusty.
Dont use root juice longer than day 14. After that you can introduce other bits of Biobizz line, BioGrow, Bioheaven.
Happy Growing !!!