Hi Pal, Firstly thanks for sharing your journey its a great help for all of us led/dwc first timers.

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I think the problem your currently having is a magnesium deficiency.. Im not an expert though and only on my first attempt myself and could probably do with some advice rather than offering it lol
Heres my reasoning though bro see what you think... :smokebuds:
Magnesium deficiency starts at the oldest leaves first then progresses upwards. Magnesium is a mobile nutrient and when in short supply will be pulled from old deposits to sustain new growth. The leafs will yellow between dark green veins and rust spots will appear around leaf tips and margins. The tips will curl up and die of. This happens from the bottom up untill whole plant is effected if left untreated. Magnesium defieciency can be casued by low root zone temperatures and acidic ph (below 5.8 in hydro).An excess of nitrogen (potassium ammonia) and/or calcium (carbonate) causes magnesium to be bound and unavailable for absorbtion. High Ec levels can slow water evaporation which effects magnesium availability. Underdeveloped root systems can be unable to supply enough magnesium for fast growing plants.
With all the above considered after reading your journal i think this could be the problem? I think you have had low res temps? the ph hasnt risen above 5.7? Maybe some root issues? plus high ec? what do you think?
I would do a res change with lower ec of 1.4 plus background (if your currently at 1.6?) and a higher ph of 5.8... I would add to my base some cal mag, root stim, silicone and some kind of revive/superthrive. I would keep res temps between 21c-23c and keep room temp 25c-27c. recovery should be apparrent after a few days.
Another quick remedy for mag deficiency is to spray a 2% solution of epsom salts on foliage. works well in soil/coco but not sure with led dwc and 24 hr light. Usually it would be reccomended to spray at lights off or low light levels. Add to that the speed of nutrient application in hydro compared to soil maybe foliar feeds are not neccassary anyway?
Im not sure what the root problem you have is or how you would go about solving it. But what about some h202 at low end levels to solve any unweanted nasties in your res? Just an idea i have no experience to go on.
Anyway thats my 2 cents for what its worth

.. Im no master grower but most of the above comes from sources written by them
Good growing karma sent your way bro and once again thanks for the grow.

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