Que la force soit avec toi.

Hello my friend, you need to flush the soil. The problem here is build up nitrogen inside the soil. To flush it out you need to use the same amount as the pot volume. So when you use a 10 liter pot you give 10 liters water. Make sure this water got a pH from 6.5 After you have done this you let the soil dry till the top layer of the soil is completely dry. Then you can start giving nutrients again. Start with 50% the first time, the second time 75% and that should be enough when I look at your plants. Keep continuing giving the 75% till flushing before harvest. Also make sure that you give water till runoff to prevent nutrient salts building up inside the soil! Enjoy your grow buddy! If you got any question just send me a private message!

It looks like there is toxicity, and deficiency signs. Which indicates that there is not enough run off at feeding to wash out old salts from prior feedings. Should get 20 to 30 percent of amount in needs to run off. If you have not been getting that much to go through, then that is the issue for sure. Only you would know this.

Looking at your diary, you switched to early from Veg nutrients to Bloom nutrients. You must keep Nitrogen high enough during the first 3 weeks of 12/12 cycle, to support the stretch. What is happening is called a "Die-Back", it happens after the stretch when the plant didn’t get enough Nitrogen during this stage of the growth. The plant is moving its nitrogen mostly from the bottom to save the top. Unfortunately there’s not much you can do about it at this stage. Adding Nitrogen will be useless, the roots are processing Phosphorus and Potassium from now on. Do not unplug the yellowing leaves and let the plant do its own job.