Temp has been sweet as mid 20s maybeWhat’s your temperature? Mine do that when I drop the temp and lower the humidity around week 8 into flowering.
Been thinking thatTo prevent yellowing fan leaves, up the dosage of N. Pretty straight forward. Not sure of it will make too much of a difference now, but keep that in mind for your next crop.
Its a common thing. Many growers lighten up on the Nitrogen dose a little too early.