Young leaves turning black from the inside in DWC

Hi brothers, I've been experiecing this issue with one of my plants from 2 days now, seems to be getting worst, ph is ok, nutrients are at 240ppm, It's cracky and really bent, I noticed the rockwool was way too moist, so I took away 700ml of water from my solution, which set the water level at the netpot base (My rockwool is 1 inch above the netpot, there's a little layer of clay pebbles below, which I really regret because it's week 3 and the roots still are not in the water). Room temp today is a little high, 26C, but wasn't when it first started, water temp is 24C, Humidity is 50%.
If it helps my lights are 200w of citizens, in a attempt to solve the issue I dimmed them to 144w, 50cm away from the bucket top

Looks like an overwatering issue man, It can happen when your rock wool cube gets water logged, always leave that air gap between the pot and the water, I usually start the water about 2 inches from the bottom of the pot. I find the bubbles popping on the surface are enough to keep everything moist enough in there to not have any issues and once the roots hit the water, the growth becomes explosive.

Hempymann said:

Looks like an overwatering issue man, It can happen when your rock wool cube gets water logged, always leave that air gap between the pot and the water, I usually start the water about 2 inches from the bottom of the pot. I find the bubbles popping on the surface are enough to keep everything moist enough in there to not have any issues and once the roots hit the water, the growth becomes explosive.

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I reduced the water level some days ago, but it didn't solve the issue, one strange fact is that one older leaves are turning black, now it happened with my other plant as well, the young plants are green, but the older bigger ones are turning black and bending/getting cracky

possibly root rot, do the roots on them look/smell healthy? see any kind of slime on anything?

Roger A. Shrubber said:

possibly root rot, do the roots on them look/smell healthy? see any kind of slime on anything?

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They're small but very white, no signs of slime, I use bacillus subtllis in all reservoirs

Looks way too young to go into the system

Your PPM is too low.