This year im trying to keep my plants at around 5-6 feet tall. So ive trained them to open out real wide. Ive grown 12 foot monsters in an industrial greenhouse, and it was a fun experience. (See pic. White Rhino in the front)
I dont test ppm when I grow in the ground because I only use water. All the nutrients are mixed into the soil. Amendments like bone meal, blood meal, fish meal, mushroom compost, etc. I also do a light top dressing with slow release pellets. When in flower, I use molasses 1tsp per gallon of water. I give them molasses 2 times a week for the first 4 weeks then lighten up to once a week for the remainder of the flower cycle. Its a simple and effective way that has worked well for me.