Heat?

Going to disagree with my growmies here - I don't think you're overfeeding except the calmag which I think you've tripled what is recommended - dial it back to 1 tsp/gallon (and this should be given ONLY once a week)... but I am confused as to why you mix up the nutrient line. Pick one brand and stick with it unless it's a specific "this is all we do" kind of nute like Terpinator... each brand formulates their nutes to be complimentary to themselves. You're using Fox Farm (Big Bloom, CalMag) as do I ... and I will really disagree with my growmie's advice to add Grow Big... I find I use only scant GrowBig early in my plant's life and then actually cut it out by the time they're the age of yours... HOWEVER, I also add Tiger Bloom which gives a small dose of nitrogen (GrowBig has much more nitrogen and plants in flower do not need a whole ton of it). And you'll see, if you look at my recent diaries, that I use DOUBLE the Big Bloom you are using ... and even use it as the main nute when my plants are small. Bottom line, for me, on your nutes is that you may have an odd mixture of nutes that might be working against each other... you'd have to do a good analysis of the chemical compositions to see if you're doing anything wrong there - and if you simply stick to one nute line and follow their schedule, you wouldn't need to be a chemical engineer! With all that said, I think the MAIN problem will be solved by what you have already done - raising your lights... In general, your grow looks really good and you should be pleased! Good luck!