Cupping + spotting

I'm negan said:

So do you anticipate any problems from "light stress" at the current height i showed above? Or is that where i should have it anyway to get more ppfd out of a cheap light? I think they were actually stacking pretty damn well at about 30 inches.

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About a pound?

I'm negan said:

Light stress is a myth. You can have too much heat but not to much light. I know this isn't a popular opinion but the data backs it up. Under optimal conditions a cannabis plant can handle more light than you can possibly throw at it while maintaining temps. The real problem is people don't give them optimal conditions then blame the light intensity.

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A lot of home growers don’t have perfectly optimized environments or the resources to dial it in that tight so “light stress” happens and it’s easier to dial back your lights a bit than run an extra humidifier, increase air conditioning etc. the term might not be completely accurate, but it works.

Two days at 75% light intensity and the cupping is getting worse.

The spotting appears to have been stopped with a thorough flush + cal mag.

I cannot figure out what's causing the cupping. I cut my light down, and raised my fan wayyy above the canopy.

The worst cupping isn't even on the tallest plant either, and it's only on the top layer of canopy. I have no idea wtf is going on here.