Robertsanswered grow question 4 years ago Appears to be magnesium deficiency. if it was light colored and raised looking it would be potassium deficiency. Cal mag is your answer. As long as your soil ph is right via reading run off. If ph is off might be a lock out. Unless your growing in coco coir. Then cal mag is needed regardless. Good luck and happy growing 🌲🌲🌲👊