Dry spotty leaves - cause?

Zinc deficiency?

Charts like this are quite useless in my view. They confuse more than they help. The issue is almost always either watering or PH. If not, then it's overfeeding (clawing/burnt leaf tips) or underfeeding (yellowing leaves on the bottom of the plant) the only exception to this is cal/mag deficiency which is easy to diagnose by mixing a foliage spray and misting both sides of the leaves. It should respond in few days given you've addressed potential watering/PH issues first.

Thanks! I'll keep this around.