Dude looks to me like you might have a lockout condition.  Your leaves are showing multiple symptoms.  And by my understanding.  I think maybe your nute feedings are too light meaning volume wise.  You said your bags might be light about 3 gallons of 60/40 mix, but your feeding 1/3 of a gallon of nute solution?.  So I'm thinking you aren't getting any bit of run off, so the nutes just stay and stay and stay.    I grew and am growing Sour Diesel auto's in 3 gallon fabrics in coco.  And I don't even get any drip from bottom until after almost of a gallon of water has been put in.  Also at 10 weeks those buds should almost be finished.  I think your plants are starving.  I also use Fox Farms Big Bloom, Grow Big, Tiger Bloom, Open Sesame, Beastie Bloomz, and Cha ching.  Big another thing, I think your math is wrong.  So apparently there is a 1.8 diff in ph going in (8.8) and ph coming out 7.  So that means if you poured ph'd water which I think should be 6.2-6.8.  At the higher 6.8 and deduct the 1.8 your soil ph would only be like 5!   I also just noticed you said you flushed with .75 gallons of 6.8 water, I think your not using enough water man.  Sorry for the long winded answer. Good luck.