Help!! Leaves are turning yellow

[scottg]

I have 2 plants that are the same breed same soil same nutrients using LED lighting one off the plants the leaves are turning yellow the other plant is fine.
Please advise
Thank You

https://imgur.com/a/FvYQtb2

 

[Bluey]

What EC, grow medium, pH, model of light and distance or DLI/PPFD?

 

[Rwise]

Luvely fall colors!