Burmeseanswered grow question 4 years ago Hey friend, It's difficult to say exactly when you don't know your pH and ppm of your water(solution) and your run off.Try to know your pH and ppm first, then you can diagnose your problem easily.But I can tell you is, it's looked like Calcium deficiency to me.Cannabis plant needs a lot of Calcium and Magnesium than other plant.If your using Tomato feed, try to add more Calcium and Magnesium supplement.Don't forget to check your pH and ppm.Happy Growing.. Peace