HMS Genetics

iron deficiency is usually seen first on bright yellow new leaves, and the symptoms of it can sometimes appear alongside other cannabis nutrient problems or deficiencies. An iron deficiency is usually caused by problems with pH, though sometimes can be triggered by a stressful environment and may clear up on its own after the period of stress is over.  iron deficiency can look similar to a magnesium deficiency, but an iron deficiency will affect newer/upper/inner leaves, where a magnesium deficiency affects older/lower leaves.