Potassium excess, PH or calcium?

calcium. also make sure your water is dechlorinated. if you have any other questions, feel free to message me 🤙

potassium or/and calmag deficiency.

Plants do not "direct" energy anywhere..........healthy leaves, damaged leaves all get their share of energy. All energy gets used equally throughout the entire plant, there are no brains deciding where energy should flow. There is no need to prune off damaged leaves until they are completely yellow. Damaged leaves do not "eat up your plants' resources" either..........leaves store resources for the plant to use. Damaged leaves will be recycled by the plant, providing the plant with a ready made store of building blocks. Remove the leaves , you also remove this vital resource of pre-made goodness. The damage is minimal, isolated near the lower areas around the fan it seems..........why worry too much. If it were nutrient related, the issue would be wide spread and affecting leaves over the etire plant. It is most likely to be mechanical damage caused by the leaves rubbing on the pottters when being wind blown.

I also think it's coming from the fans; it really looks like windburn. First of all, adjust the fans! If your plants are affected by windburn, the fans are either too close, set too strong, or both. Move them further away and/or reduce the wind speed. A light breeze is enough to maintain air circulation and strengthen young plants. You don't need to mimic a hurricane! Prune your plants. A little damage can be repaired, but if it's too severe, it will drain your plant's resources. It's worth cutting off heavily damaged leaves so the plant can direct its energy to the still healthy parts instead of transporting it to the damaged leaves.

only near the fan? if that fan is functional, it's a likely candidate to blame for damage shielded leaves at bottom don't stay picturesque forever, either.