Robertsanswered grow question 2 years ago Looks like a calcium deficiency. With being in flowering I would check your substrate ph first. Flowering tends to draw a lot of phosphorus which if more is not added your ph will climb out of range. Or if too much is added it will drop down below range. This can cause the lock out and the plant can't absorb nutrients right. Now If your ph is in range then it is the calcium. Would be the steps I would take.