looks like the onset of a pretty good K deficiency along with mg-usually comes from high levels of salinity. im guessin u never flushed? also those nutes do not sound good for your Sativa, they usually like less ferts and that P is way out of balance. maybe a shot of this stuff last couple of weeks before harvest, prior to final flush.
you see those crispy leaf edges in that first pic? like it or not, most of them are now going to look like that throughout the plant, from what I can see. dont bug out.
if you are using tap, is the water considered hard?