About 18" from the canopy… canopy temp fluctuating a bit but averaging 75 no higher than 78. Fed them last night and they still look about the same today. No nute burn or any other signs of lock out or deficiency that I can tell. I’m hoping its just stressed from switching lights
That is a lot of light, compared to the HPS 250! With LED it is the intensity that usually creates issues, not heat. Turn it down or raise it up? Website says 8" from canopy, and you are at 18! They should bounce back.
Just jumping in here…I would just let them get accustomed to the new light levels.
Remember, they will need more water and nutrients at the higher light levels.
I run ppfd at 900 - 1000+ on my plants from about week 4 through to harvest without issues.
It’s up to you. At 800ppfd for 12hrs you’re hitting close to 35dli which is where you should be in flower. At 1000ppfd you’re hitting 45dli and where you’re approaching levels that will need co2 supplement.