Looking awesome so far! Keep up the solid work!
In regards to the fading leaves I think it could be two things:
1. pH could be a tad high at 7.5, I would try lowering to 6-7 for soil, anything above 7 and you start to lockout half the nutrients. (https://www.growweedeasy.com/ph)
2. If the above doesn't work they could just be looking for more food.
Cheers,
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