Feed 6.3 ph. Run off 5.6. Idk what the ppm is. Week 6 of flower
Without knowing the details of your grow I’d say calcium deficiency most likely. Are you using cal-mag.
Using cal mag
Can you share more photos of overall plant/plants? When was your last feeding? Ph is too low to pick up the calmag even if you are feeding her. Are you in coco or soil? If soil need to bump up to 6.8-6.9 to correct ph
What is this? Are they bugs?
Close up of a leaf. Pictures above are back of leaf
Just gotta keep watering until ph is in line. Looks like they could be aphids but I honestly don’t know 100% based on photo - would need a solid focused shot of insect to give you conclusive answer. Lady bugs should take care of these guys regardless if they’re aphids, thrips, or mites (my 3 possibilities).