Looking great sir! The yellowing could be pH issue that will cause deficiency. Strain can determine a plants preference in pH levels and nute requirement. Some might prefer low pH and heavy feeding, while others prefer the opposite. Good rule of thumb is to check your pH at any sings of deficiency to avoid lock-out. Yellowing is usually related to some kind of deficiency. They also tend to demand more nutes, because of the increase in photosynthesis rate, due to the intensity and spectrum of our HI-LEDs. This is especially true with magnesium and calcium.
Lower it to ~20" with no lenses for flowering.