Delps8
Well-Known Member
I don't see any indication of excess light - tacoing or other photo avoidance.looks like nute burn how far are your lights from the tops & what light strenth are you at PPFD DLI? what medium are you growing in?
I'll put a small wager on VPD being high (tip burn)
[time passes - zooms in on temp and RH values]
That temp/RH gauge looks like one I saw in a thread last week.
80° and 40% = 1.9
Cannabis does well at 1.2-1.4 in flower. At 1.9, the plant is taking up and pumping lots of water because it's so hot and dry. Unless PPM is dropped, there's a lot of chemicals going into the plant that it can't process. That leads to tip burn and/or a nute imbalance.
I hit the same thing in my current grow switching to flower. I tried "Bloom" nutes (put a big dent in my bottle of pH Up) and, when I switched back to regular nutes at 640/500PPM, things did not go well. I had to drop to 540 and 470 before it stopped. Doing fine now at 390/500.
It's mpossible to say that the high VPD is the cause with this grow but this is a great example of VPD that is extremely high.
When you hear hoofbeats, think horses not zebras - the Amazon man would be dropping of a humidifier most tick if that was my grow.