I will start my bloom food about 10 days from bloom, usually at the on- slaught of pre-flowers and floral arrangement. This is your plants way of saying, I'm ready, so that is when it begins. When they make their phisical changes, I make the nutrient changes. I grow useing raw essentials all organic. tea nutrient only I veg in soil I pre-mix before I plant. This gets them through the veg process. If i see a deficiantcy, I adjust by cold brewing a tea with worm castings and a tiny amount of blood meal.This happens seldomly. (Any MORE). It did take awhile to dial it in. ratio wise. Still much easyier to deal with mistakes. And fewer of them growing this way. I will never buy a pre- prepared nute again. After learning to recognize what marijuana needs, by a plants appearance. This is in fact the simplest way to achieve awsome results,ie huge resinouse crops of tasty bud. It says something about your nutrient selections if you have to do a flush,to achieve tasty buds. Snap a leaf right before flushing taste the juices in the stem,note how chemical it tastes. Try growing in organics, do the same thing, the diffrence is night and day. no flush required or recomended!
