its 2 leaves up top. and a few of the baby leaves on the bottom... it did it at about 2 weeks old. then stopped for a few weeks. and came backIs it only on 1 or 2 leaves? I don't think it's any kind of deficiency the plant looks pretty good
I agree with this. Your plant looks pretty healthy other then those couple leaves. Just keep an eye on it, it doesn't look like a traditional nitrogen def. to me, I don't think that is your problem.Does it stay the pale green or turn orange/brown, maybe it's just bad cell growth, the leaves themselves don't seem to be wilting or doing any curling of any kind. I wouldn't worry too much
Your RO water has no calcium nor magnesium in it. It needs it added back.RO water is 28ppm when i checked it 2 days ago. not sure what adding the calmag does to it. i will check tomorrow. i can turn the fan down just a bit to raise temps