What is causing this?

Bonjour, comme souvent il y a un insecte qui mange, quand il manque des morceaux. Pour régler le problème sans passer par le napalme, j'utilise un insecticide fait par moi (DIY) a base d'ail en décoction et du savon noir, très efficace en préventif comme en curatif. L'odeur est meilleur que le purin d'ortie ! Bonne chance.

Good point about broad mites @Mosquito , if they are there you can see them with a magnifying glass if your eyes a not the best. They will produce more noticeable webs once the population is large enough. Cheers,

Haha gotta love your name! I think that mosquito is right and that this is indeed caused by broad mites Here is a link from an article with pictures so you can compare and an explanation how to identify and how to get rid of broad mites. https://www.growweedeasy.com/cannabis-plant-problems/broad-mites Goodluck! And a happy and healthy 2023

m0use is probably right about the brown spots and nute issues - but you've also got something eating those leaves... some BT (bacillus thuringiensis) will do the trick here no matter what insect is having dinner and can safely be used on flowering plants without damaging the buds or the taste of the harvest (it's organic). The problem is going to be that you need to spray just before lights out so you're going to HAVE to give them some lights out time.... and the plant is so bushy at this point, getting everything sprayed is going to be a pain in the ass but... Good luck!

Broad mites!!

PPM is 310-330. Water temp in bucket is 20.1C. The reason I think it's a pest and not a defficiency it's because I've grown in the same exact conditions in a different location and didn't have any issues.

that is indeed very weird. the spotting to me seems like it could be calcium deficiency. The PH is a bit low for flower, I like to keep mine aorund 6.2 in flower vs 5.8. I would try and raise the PH up a bit. And like @Organoman has been saying in your other question. GIVE THE PLANTS SLEEP. he is 100% right plants need sleep. 24/0 is not natural and they do not do well in it. I get how some say its fine, and maybe fore them their version of fine is different then yours. But I think alot of this will start to lessen when you give them a dark peroid. 18/6 max for veg. fuck 20/4 or 22/2 its 18/6 in my books. Also given that you are feeding GH trio lineup and some extras you really should be looking at the EC of the feed, I would not be surprised if your medium has a massive salt buildup and these is causing the other effects to the leaves. locking things out and making it harder for it to take in. Get an EC pen and dilute your feed down to a reasonable level and work from there, they are 20$ for a cheep one that should last a few grows. This tool can help problem solve a lot of issues and prevent many more if used correctly. FYI: We will not be notified of any reply or tag [@] in the questions part of the website, if you need to reach out with other information use your DM "direct mailbox" in the bottom right hand corner of the page. it looks like a little paper airplane icon. Good Luck!