And let's see if we can get a handle on why your plants were so small for way too long. Maybe it's the genetics, so next time maybe go for a photoperiod F1 hybrid and let's get that growth rate much faster.
My thinking is the initial soil was the problem. It probably didn't promote root growth. This Black Jack grow and the one after it, Amnesia Haze, were terribly slow until I was able to coax better rooting. I used different starter soils, but I believe both were lousy.
The Amnesia Haze was growing so slowly that they were basically miniature plants. After several weeks of nurturing them, I decided there was nothing to lose and removed them from their pots. It was clear then that I chose bad soil from the shelf at Lowe's. Even though I had been watering carefully, the soil below the plant was dry and hard. It wasn't absorbing water. So, I pulled as much of it away from the roots and planted them in my soil mix. The plants quickly found the new soil and grew well, till they developed a calcium deficiency.
Now, I have them in the best soil I've mixed so far and am supplementing with Epsom Salts, Gypsum and Azomite. They look healthy now. I ordered
Great White root stimulant and inoculant and will use it the next time they're watered. After a week or two, I'll flip them. For a while, I'll have two tents in flower mode at the same time.