Athosanswered grow question 6 years ago By the look of your pictures, you already have Nitrogen toxicity (dark green leaves), you should cut back on the grow nutrients. Your cal mag dose is good enough and even a little on the high side, so I think what you experience is not exactly calcium or magnesium deficiency but lockout. Calcium and magnesium are locked out when there's an excess of phosphorous and / or potassium. The burnt tips on leaves support the theory that you are over feeding your plant.