I just ended week 4 of flower, did a good amount of defoliation at the end of week three and since then my lower leaves of 3 plants are yellowing and turning brown on the edges and tips the top of the plants seem fine ( ill attach a picture of the top ) and the leaves are definitely dying. Im in ffof running synthetics with cal mag at 6ml gal, runoff was 6.51 1390ppm on the worst yellowing one the others are right near those numbers. These pictures were taken right after a watering. Any ideas ? Thanks for any answers







Is there any possibility of nutrient lock ? Looks like a few things, the tips and edging looks like phos def and the yellowing look nitrogen def . . .
Just my .02
I will say, all the ppm measurements are stuff I do not understand.