Nitrogen deficiency

Hey TheDoctor. Thats actually a calcium deficiency - you can tell from the spots. Its usually caused by a pH imbalance but can also be caused by a lack of calcium (less often) Since you are flushing its perfectly normal for the plant to become deficient in calcium as plants take almost as much calcium as they do phosphorus. During the flush you want to get rid of nitrogen and calcium. This is because they contribute to that bad "fresh cut grass" smell and taste. So definitely dont add nutrients, just keep flushing them and ignore any deficiencies. I sometimes let my leaves go crispy and yellow from lack of calcium which has a direct effect on the smell and taste by getting rid of that "harsh" or "grass" taste which is mainly caused by nitrogen and calcium.