Looks like potassium deficiency. What nutrients are you using, how much, how frequently? Do you know what the run off pH and ppm are?
How close is your light as well?
Could be cal mag but not sure
I see why you'd suggest that, if he is in Coco, possible. I'm guessing the plant is 4-6 weeks in flower where I rarely see a Ca/Mn deficiency, but not impossible. @jaysupreme100 what medium are you using?
I’m using 2 tsp general hydro flora nova bloom per gallon I’m in fox farm ocean forest I keep water ph around 6 I have to test runoff on my next water my light is about 2 1/2 feet from the light I don’t think I can raise it up much more
@jaysupreme100 Check runoff pH and PPM and consider increasing feed pH. Cannabis grows best in soil that is in a pH range of 6.0-7.0
@mwhite9829 Feed about a gallon per plant and give 2 days off. I‘ll do some research on that though thanks