Boron Deficiency?

Hello cannaman9, that looks like the early stage of a magnesium deficiency. If you fix the root of the problem, further yellowing and discoloration of the leaves should stop almost immediately. Some of the affected leaves may recover somewhat, but what’s most important is to make sure the problem isn’t continuing to spread to other leaves on the plant. Good luck with your project, I wish you all the best! 👽

it's probably Ph related or you've gone too far on the Calcium.. If it's one leaf.. Clip the one leaf problem solved ha haha :). If it's quite a few leaves it's definitely calcium the likelihood of seeing micro deficiencies in modern cannabis nutrients is crazy talk. So many people are using way too much. In my opinion it's got more to do with a Lack of balance then it does a lack of Boron. But good on you for trying to diagnose your cannabis plant. If you see damage in my diary it's 90% related to ph... And now your know because knowledge is power :).