Help needed identifying deficiency

a friend of mine asked me if I knew what he was facing here with the plant pictured, I'm not that great with identifying deficiencies and from what I've seen from doing a bit of research, is that it could be a number of possible issues.. so any clarification would be very much appreciated!

My guess would be pH related but could indeed be a number of possible issues.

Can you give some more info about the grow?
Medium: soil/coco/hydro
Nutrients
Temperature
pH both water and medium
...

I agree with above ... and those spots may be Calcium deficiency.

So in the absence of more info ... wrong pH is preventing Ca do its work of shuttling minerals around yr plant/s.

firstly check pH and correct. then wait and see how yr plant performs ...

It might also be the pH swinging too much through their day as well but it looks too low.. Did he add anything to buffer his soil like dolomite?

Anyway as mentioned check pH..

Check pH first. If that is off fix that.


It looks like a Mg deficiency most then it looks hungry as funk!

As well, mix 1/4tsp Epsom salt with 1gal of water and gove those ladies a foliar spray. If using a heavy soil mix cover the soil previous to spraying. You should see visible improvement within a few hours. (I am doing exactly the same at this time for some generally hungry plus Mg deficient plants).


My next step is to mix up some Maxibloom and give a foliar of it.


According to research I've read on an Aussie agricultural site (sorry no link), foliar sprays (mixed with Fulvic Acid) are up to 20X more effective at nutrient delivery than root based nutrient delivery.

I have similar brown spots on one plant leafs there is shitload of calmags in coco so its probably not calmags def. tried to feed her bloom nutes/phosphorus and waiting for the results.. btw plant is in reused coco other one in new coco and that one dont have those brown spots hm.