Is this a magnesium deficiency?

@Rojays81, nope, only on some big fan leaves, now it's expanding on all fan leaves remaining and it's starting to show on some normal leaves.

Exact same all over?

Hi GoldenGromie, thanks for answering!! I use some of the BioBizz line (BioBizz light mix soil, Bio grow + bio bloom + top max) so I’m 100% organic and I never bothered about pH or ppms.This thing that is happening to the fan leaves of the plant it’s a thing that always happen to me towards the end of the grow, so It doesn’t really bother me also because in a week or so I will flush; I was just curious of what it might be.

Hi there, Im not sure what kind of water you are using. My leaves looked like that due to excess iron, if you are using city water or RO water then it probably isnt that. The more likely problem is Phosphorous or Potassium deficiency (could be excess too). Along with that it could be due to lockout or too much or too little feeding. PH lockout if your synthetic is the most likely. If your organic, you wouldnt have 90 percent of any of these problems haha. Switch to Gaia Green or Doctor Earth and worm castings thats the easiest best way to grow and not have to even think about ph usually. Please check out my grow and give me a like I use Gaia to grow. Good luck!