I'm having some trouble diagnosing the problem in my fogponic grow. I'm thinking it's Magnesium, but not sure. I'm running GH Flora series at low level, with Superthrive and H2O2 added to the res. 5 feeding cycles a day, 30 min on.
Ph fluctuations Unstable pH values can affect the nutrient intake of your cannabis plants, resulting in brown spots appearing around the middle and lower parts of the leaves of your cannabis plants as a sign of stress. Learn more about PH Fluctuations Phosphorus excess An excess of phosphorus will result in mottled or mosaic-patterned leaves. They will darken in tints of green, blue, or gray and the lower leaves will thicken and show bronze, purple, or brown spots. Phosphorus deficiency A deficiency of phosphorus will be visible on the leaves and stems. The leaves will yellow, twist and curl, and its tips will show burning and die off. Older leaves will start falling off. The stem will start to color red or purple and new growth will stunt or look twisted. Even the roots may show rot. Learn how to handle a phosphorus deficiency.