GrowerOGanswered grow question 3 months ago Hello mate, i think you have at least one or two week before the harvest so the discolouration of the leaves could be the normal proces before the harvest. The pH at the 6.5 is the up limit of this period, you could reduce you pH at 6.2. The last hypothesis is that some drops of water fallen on your leaves and with the ligth on the leaves burned.
Good luck and happy journey.