I see. Well I'm a beginning grower myself, just started in June. Still battling with the issue of knowing exactly how much to use. This is how I do it (I use soil less medium with NO nutrient amendments within it):
I start all plants off with about 1/8 teaspoon/gallon (seedlings), or 50% less than what the manufacturer recommends. Then, I continue using that amount as long as the leaves stay a healthy green; until the plant is showing a nitrogen deficiency. The leaves will start getting a lighter green than they should be for each specific plant. Since the plant will show that first, you can assume that the plant needs more nutrients altogether, before other deficiencies show.
So, then I move up to 1/4 teaspoon/gallon (seedlings/vegging plants). I then feed that much until the plant starts to show signs of nitrogen deficiency, indicating the amount I'm giving isn't enough to sustain the plant's growth. Then I move up to 3/4 teaspoons/gallon once 1/4 tea/gallon is not enough to keep the leaves a healthy green. Since I use soil less, I feed EVERY watering, so with soil you wouldn't necessarily need to do that. But definitely read the plant and up the nutes when the leaves start going light green. Then feed with plain water or diluted nutrients while the plant shows it's healthy and green (from top to bottom)--depending on how many nutrients are left in your soil. Unless you want to "push" the plant with certain bloom boosters, etc.
IMO, heavy feeders in flowering will suck up nitrogen from the bottom leaves first---and quickly at that. Like my Northern Lights plant. Right now, in week#4 of flowering, I still find my plants (OG Kush too) needing lots of nitrogen, so I give them 50% bloom and 50% veg (Foliage Pro). Not sure if I'll change the ratio as long as I see the leaves yellow up within a couple days of not having enough nitrogen in their pots!
Hope that helps!