The image shows what is happening to all my leaves, including the ones around the flowers. The plant itself is well over a meter tall, and about the same width around as well. I have carefully trimmed the plant so it is bursting with many good long flowers. It is right now about 3 - 4 weeks from final harvest, and has long, full buds and colas that are about 10% amber colour at this point.
We have an outdoor hydroponics system 900 mm square, 150 mm deep, with a bamboo frame and bird netting. There is a large nutrient tank with an electric pump fill/drain system which fills and empties the trays every 2 hours. The plant itself is in a large (300 mm diam. x about 300 mm tall) pot of garden soil set down into the hydroponics medium (perlite), with drainage gravel at the bottom of the pot and holes all around. Besides the watering system mentioned above, she has her very own hose/valve split from the main fill hose, which empties the nutrient water into her growing pot itself at the top and drains out into the hydro tray (to help flush out harmful salts buildup) and so through the regular drain and back into the tank.
The pH is perfect at about 6.2. The nutrient levels are ec, ppm = 6440 us/cm, 1800 ppm
We had this spotting problem in the very beginning, but some trace elements (manganese I think) fixed it. It grew amazingly and did not have any problems until now, so close to harvest. Now all the leaves are getting covered with tiny yellow spots, with some darker spots along the veins, and some darker tiny spots along the veins and stems behind.
I would really like to wait the extra few more weeks before harvesting to get the best yield, but I’m not not sure that I can save these leaves and had rather harvest early than risk losing the lot. If need be I can blow down the whole tank and fill with plain water for the final 3 weeks or so.
Any help will be greatly appreciated!