Wow man, looking good! Nice setup and I'm glad you aren't trying to jam too many plants under that 400w! I little creative bending and trimming during your next veg will get your canopy nice and even to maximize your light penetration next flower. Your shot from above looks great. I see what you mean about the yellowing on the side view though. Older sun leaves will start to die out. I have trimmed them off in the past, but now I wait until they break off when a small amount of pressure is applied, unless they look really nasty, then I trim them just for looks. My logic is that the plant will let it fall off when she's fully done with it. I cannot fully tell from the pictures if the yellowing is spreading toward the top of the plant, but the aerial shot did look pretty good.
I am not personally familiar with your nutrients or soil, but loss of green can indicate a nitrogen deficiency. In my experience plants like consistency though, so don't start experimenting just yet, if it remains just the older sun leaves then I think you're ok. One thing I would do is dial in the PH of your water/nutrients. Forgive me if you know, but alternate feedings nutrients/water/nutrients/water, flush adequately with just water during the last week or two, and always PH it to the exact same number with a digital PH meter. If I'm doing a cloner or something then I do 6.5, when I'm watering or giving nutes it's 6.8. I don't test the PH of my soil, just the water I'm running through it.
Personally, I like to have my oscillating fan really making my girl dance because her flowers always get too big for her branches, so any additional strength I can get her to build may eliminate a stake late in flower, but if temps are an issue, then creating more airflow directly beneath the light may be helping you.
I opt for promix HP (WITHOUT the fungicide), Superthrive (veg only) fox farm Grow Big, Tiger Bloom, three part solubles, Dark Energy, and Fossil Fuel humic acid (these last two are not by Fox Farm). Good luck!
