Or the panels , are really pushing the PS limits of the canopy..(photoinhibition /photorespiration....)..
I'll vote for photoinhibition.
Or somethin' is going wrong with substrate's EC /pH .....
Well whip out Mr. PH and EC meter and do your thing my brother.
Please let us know...........
But.......
It looks like the exact same thing, that I am seeing in certain locations in my grow.
Basically, over my tables, the light sweeps from HML pro-grow HPS.
Where I am seeing this is under the pro-grow.
(There is also some interesting photomorphology when plants are moved under the HPS for the last 30 day)
But for now, I would like to focus on the interveinal chlorosis at flower set. This current run also has the slightly burnt tips just like yours.
Well I would like to enlist your help my friend for an experiment.
I can't do this my self, because I've already half proven it (maybe) in my grow.
Considering........
The HML plants are pretty as punch. The pro-grow plants.......same as yours. Hmmmmm.
The difference..... HML=nw and ww and a little 660. (homogeneous more or less)
Would you make a panel or two all whites, your choice of mix though all nw would be better for this use case.
I would like to see if that fixes the problem in your grow with the other variables more or less the same over the first 30 days of 12/12?
This would be of great help and either help prove or disprove some of the theories on white light, wave form, and maybe even light pattern management.