I use lucas formula in veg. Basically 1-2-2 or you could say it's 5-10-10. In flower I switch to using maxibloom dry lately. It's 5-15-14. Sometimes in late flower I'll use koolbloom dry with a little flora micro. KB dry is 2-45-28. I haven't switched to the KB dry yet and I may stick with the maxibloom this time because they look like they are already low on nitro. Can't reduce the ratio more yet. I get yellow leaves from the powerful lights on the top. Right under that is green though and the shaded smaller plant is darker green. This is 6 1/2 weeks from flip. Took it last night. They have 3 or so weeks to go still. Lots of white pistils. You can see how yellow my top leaves are. I like to let them change to fall color. Many cannabis growers feed too heavy. You don't want them green to harvest. They get a more natural ripening and terpine profile like this. You can see some purple leaves in there. I'm usually near half recommended strength but I feed daily. My flower plants get 1 gallon each a day right now. Small right front plant skips a day but the others are every day right now. This is also called ACE grow method or Autumn Color Effect. Good article on it. https://howtogrowmarijuana.com/autumn-color-effect/
Like Tbone said try tying the top down. See photo- It will help bush out your plants and maximize your canopy.