flowering

Flowering?.. Dieing!.. These need to be fed. These plants have a deficiency of everything. Not checked your diary but, guess it's coco, you havnt gave enough or any Calmag, not enough nitrogen intake and when that happens it's not taking anything in. Give a balanced feed with Calmag. Good luck.

Give them so food, please. They are crying for it

The yellowing seems like early nitrogen deficiency kicking in after the stretch pretty common at this stage of flower. You could give them a light N boost or just let them fade naturally if you’re close to the end. Solid canopy and nice spacing though