I just use some canna additive 1/3 than recomend using. My soil just have perlite, perionyx (50/50) and some eggshells.
I think close the distance of lamp to plants as much as i can will make more canopies. First i have used 50w cfl for all. Then I added more small leds and cfl... until plants were growing up enough to move from box 0.8x0.8, I added hid lamp 250.
Gradual harvest based on trichome checking is a fairly standard practice. Make sure to check the top and bottom of each cola in multiple spaces before deciding if a branch should be taken.