I’ve noticed that Fox Farms’ feeding chart indicated that Grow Big is to be added during flower along side Tiger Bloom. Other searches seem to indicate that one is to cut Grow Big since Tiger Bloom can handle the flower phase. I am currently doing only Tiger Bloom for 5 auto-flowering plants and 4 or them are ok, but the 5th, a much larger plant, seems to be dropping all of its big leaves and she’s running on sugar leaves alone for photosynthesis. My thinking at the moment is that I’ll give the big girl a bump of Grow Big because she has so many colas to maintain and could maybe benefit from more robust vegetation. My concern would be hitting a lockout situation from over feeding. I’m using Ocean Forest (now probably depleted), 5 gal fabric pots HLG 260 Rspec & bottom feed RO water/top feed water/nutrient mix of calmag, tiger & epsom salt.
Nitrogen is necessary to support the plant throughout its life. Nitrogen is particularly important during the first 4 to 5 weeks of flowering when the plant growth rate is at its maximum.
You should also be using Big Bloom, as it contains the micronutrients (iron, boron, copper, manganese,…) your plant needs.
Do you know your runoff pH?