Athosanswered grow question 6 years ago It's not going away because it's not N deficiency, it's potassium (K) deficiency, quite common in flowering stage after the stretch. Carefully check the lower leaves, yes they are yellowing, but it's not homogeneous like with N deficiency, it starts at the leaf tip with the leaf base still green, also they show rust spots, classic K deficiency. Stop with the veg nutes and change to bloom. 1.7 EC run off is actually quite low, as long as it remain constant or ir goes down, don't worry.