What's wrong with this?

Hey, I have these brown spots on my leaves... I'm at day 18 and there are a few possible causes but wanted to check in. I stopped feeding nutes since I thought this was soil acidification. But when my plant was young I had a plastic bag around it. I woke up to see a fly in it. Third possible cause could be because I accidentally sprayed my leaves with Water mixed with fertilizer. It did make some marks but these guys seem expanding... Ask any questions I'm 99% online. And thank you all for your replies

i have similar problem on my auto plant. my best guess is nutrient burn or incorrect ph. trying to fix that problem myself by flushing with ph balanced water and giving my plant a rest. (its not working yet that brown spots are spreading)
good luck my friend i hope u fix ur problem.

grou said:

i have similar problem on my auto plant. my best guess is nutrient burn or incorrect ph. trying to fix that problem myself by flushing with ph balanced water and giving my plant a rest. (its not working yet that brown spots are spreading)
good luck my friend i hope u fix ur problem.

Click to expand...

Same here mate, i know its really frustrating...

researched alot today and found a thread which associated to my problem https://www.growbarato.net/blog/en/burns-cannabis-leaves/
fan burn is the best guess on my problem, check it out maybe you find something interesting. good luck