Heat burn or overwatering?

[VACSADX]

Hey guys!
On my 4th grow (3rd indoor) and faced some health issues for the first time on one my plants.
A few large leaves became dry and crispy and getting yellow-brown-ish.
Looking up the issue I found it could be from either heat burn or over watering, what do you think?
The other 2 plants in the same environment and roughly the same size are all OK.

 

[PotDaddy]

I would go with over watering but I am sure someone more knowledgeable will be along shortly.

Goodluck

 

[Geordiejesus]

Could be a calcium defficenies.

 

[VACSADX]

Thanks for both answers! I'll water her less and add calcium too!
Also moved the lights a bit up, better safe than sorry.

 

[Geordiejesus]

If you are using coco medium calmag is definitely needed

 

[PotDaddy]

If your using Leds you probably need to add calmag. Or this one is a lighter feeder than the others.
Try not to make too many changes all at once or it's hard to figure out where you went wrong or right.

Goodluck

 

[VACSADX]

If your using Leds you probably need to add calmag. Or this one is a lighter feeder than the others.
Try not to make too many changes all at once or it's hard to figure out where you went wrong or right.

Goodluck

The nutes I'm using has magnesium, but no calcium, that could be the issue then.
I had the same strain before with no problem, but for that I actually added calcium, this time I didn't, so I'm going with that for now!

 

[VACSADX]

A week later she seems to bounce back and started growing again after a few days of stunt!
Only one question remained, should I cut the affected leaves or not...?