Seemingly unstoppable yellowing during flowering phase

High Hieronymice, The cause of this deficiency could be pH issues or overfeeding. They both cause nutrient lockout so it doesn't really matter what the cause is. But it does matter that you can fix both of these problems with a good flush of your soil and I will explain you how you can do that the best. You can do this flushing by slowly pour water pH 6.2 onto the top of the soil, allowing it to drain freely from the bottom of the pot. Pour slowly, so the water doesn't overflow from the top of the pot. Use approximately four times the pot's volume in water to flush the soil. For example, use 1 gallon of water for a 1 quart pot. After the flushing you need to let the soil (almost) dry out completely. From there you can start giving water with pH 6.2 and nutrients but do not exceed EC 1.8 to make sure that you don't overfeed them in their last weeks working hard making those buds bigger, fatter and juicy! Happy Growing! 😋

Eh, I doubt it is due to nitrogen. My guess is either improper watering or your pH is off. Get your pH to 6.2-6.7 and only give it pH'ed water for a week. See how it does from that and go from there. I hope this helps.

I would invest into a EC/PPM pen to confirm the strength of your feed, a high ec will lockout some nutrients and make it look like a deficiency. Also a incorrect PH will do the same like GrowingGrannie said. I aim for 6.4-6.5 in soil based grows from seed to harvest. It what has worked best for me sometimes I let it get a bigh higher up in the end of the grow to aorund 6.8. So first would get your EC/PPM checked and monitored then calculate the NPK ratios and amounts your are feeding the plant, from there move onto deciding what is the best course of action to remedy the plant. Good Luck! ***disclaimer, multiple people are answering all questions as there is a contest called GOTM, when a user is selected as the answer they get a point. Please see the contest page for information regarding the details: growdiaries.com/giveaways/GotM-August-2022 Please note, when you reply to anything on the questions part of Growdiaries website, no one will be notified of this. Not even if you use a "@" tag in their name. Best to reach out to them in DM using your inbox, it can be found in the bottom right hand corner of the site. It's the small paper airplane button, it will be highlighted green if you have new messages***

This has nothing to do with nitrogen - the flowering stage doesn't need much nitrogen (although it DOES need some) but using too much of it can cause problems such as locking out calcium (which hasn't happened to your grow YET)... This is most likely a zinc deficiency and the culprit is your pH... you need to get this down to 6.0-6.2... other micronutrients are going to be affected as well - such as manganese and copper... so getting the pH under control is vital. Your damaged leaves will not recover so don't look for that to happen... but once you get the pH down, you shouldn't see more of this happening... Good luck!