Addressing defiency/pH/light burn

Starving for potassium. Add a P/K booster to your feeding line up.

I feel your plants are acting this way from a buildup in the medium, need run off with feeds or it will buildup in the substrate and lock shit out. You also don't want the fans pointing directly at the plants, oscillating over them is ok, but right on them blowing is stressful for the plant. Your using a powerful LED and 18" might be to close for it despite that being its recommended hang height. The leaves are showing light stress to me with the tacoing. Temps seem on point. As for the colour and differences in the plants, unless they are clones they will have their own unique traits. seeds are like brothers and sisters, and custom seeds are a mixed bag. I think once you start getting a good runoff and fix the salt buildup the plants will start to look nice and lush again. Good Luck!

Hello my friend, the leaves on the right plant are tacoing and this is the sign that they are having heat stress. The easiest way to solve this problem is by moving the lamp up and further away from the plant if possible. If this is not possible then place one of your ventilators in a position that it blows the wind in between the lamp and the plant. The deficiency and discoloration is caused by a nutrient lockout, you are overfeeding and nutrient salts builded up inside your soil. They raise the EC and pH. To solve this problem you need to do a flush. Here is an article about how to do this, https://cleanleaf.com/how-and-when-to-flush-cannabis.php