ScrOG of two Kush

Noticing a few leaves on the Bubba Kush exhibiting some pale leaves in the middle and upper areas whereas the OG Kush are still a darker green. Both get the same nutrients and share the same conditions. Maybe the Bubba is a bit more sensitive to the dry air as one pale leaf feels a little brittle. Couple of leaves on the OGKush have yellow spotting appearing. Will maintain current nutrient levels for the time being including Cal-Mag unless the spotting gets worse