Yellow Leaf on mid flowering stage.

High Captain, The cause of this dificiency could be pH issues or overfeeding. So to find out the problem here you need to measure the pH from your soil to make sure that this is not the cause. I will explain how to do this. And if the pH is in the right range then you need to flush the old nutrients out of your soil so you can start giving the right amount of nutrients again after doing this. I will explain you how to measure pH in soil first. And how to flush the nutrients out of your soil after. For measuring pH in soil just follow these steps. Your pH should be around 6.2. 1. Place soil sample about ¾ full in sample jar and add distilled water to cover soil. 2. Cap the jar and shake the soil vigorously a few times. 3. Let mixture stand 10 minutes to dissolve the salts in the soil. 4. Place the pH tester into the wet soil slurry. 5. Measure pH and record measurement. If the pH is in the right range then flush out the nutrients 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. Happy Growing! 😋