Uv lights during the 48 to 72 hours dark period before harvest

So I have done it once before and I am going to do it right now but has anyone ever tried only running uva or uvb lights (mine uva) during the dark phase before harvest? I did it once for 2 days and the third day no uv lights and when I harvested the plants they went from some purple and green to sold purple almost black and it immediately skipped the dry phase and went to curing in the jar holding at 63% humidity. Anyone try it?

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Don’t see how this is even possible.

I use UVA from week 3 of flower to the last week before the chop. Incorporate at lights on. Using it for only 2 days will not achieve any desired results like I do it for more frosties. This isn’t going to happen overnight at the end of her life. Sounds like more Bro Science without specific back up.

UVB can only be used in very small amounts/duration. Not recommended.


Hey @Synganic_grower ive also used some UVA during my grow. I start mine about 3-4 weeks before flipping my lights to 12/12 initiating flower.
Outside plants are getting UV throughout the year at different intensities with peak Mid-summer.

UV photons carry more energy than the blue-red variety so you don’t as much.
Just something to tickle the dragon.


i use it for more then the 2 days, i do it almost its whole flowering phase, im just saying that it happened to me while lt was in the dark phase and was wanting to know if anyone else do a dark phase with only uv lights on

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I have a 5watt UVA bug zapper that is on 24/7.