I am pretty sure my Purpling was caused by uvb as it was not in the middle where the most uvb is given when the light mover pauses at the ends. Left it on anyway and now middle leaves have turned darker than purple with brown spots. I think they have uv burn. So maybe there is such a thing as too much ;-). Have turned off uvb for now. Perhaps last three weeks would be better if you have full diverge close to plants like I do. If it is far away or you have to move them around manual then maybe all the time is fine. Could also be strain dependant. I expect my sativas are used to more uv...
Oh well need to experiment more.
Congratulations on the harvest!
I disagree about the uvb causing the plants to turn purple. I just removed out of my garden 8, 26w Reptile UVB bulbs that I was using for a quite long period and to be honest I didn't notice any benefit from it, neither any purpling in all my past grow. The purple could be caused by the LED's itself or, your temperature getting low (Not too low, but low enough for that specific strain)
I have a Cotton Candy in my garden right now starting to get purple at temperatures around 72, all the others are super green.
I sent you a private message.
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