Originally Posted by Phaeton
I can see Denali from my front window so when I did my UVB tests I started with the level calculated to be present at the top of the mountain.
The leaves were actually brown and shriveling by the second day.
Dropping the level down until the plants quit dying found no increase in THC production at all.
Between 50 uw (microwatts) and 200 uw the plants lost 3% to 20% of their yield.
Most plants left it at that, smaller and slower growth.
Some plants, while not increasing THC, delayed the onset of the high. And in addition, the high lasted longer. This happened more with select Sativa hybrids, although it is hit or miss because the breeding is done for THC levels rather than UVB sensitivity.
I use UVB from seedling to harvest, a couple weeks at the end never did make any difference, it is a whole life experience or the plant does not respond.
I like creeper weed and use 75-100 uw on all plants, the price is small. This is not enough for severe stunting but adequately creeperizes susceptible plants.
My current favorite is Obi-Wan, it sucks up UVB like a vacuum grabs popcorn.
I used a 4ft t5 uv bulb a few times. About 95µW/cm² according to the bulb.
No idea about thc levels, and didn't really notice any creepers.
But I noticed some heart palpitation weed in the uv batches that I didn't get in non uv batches, which I didn't care for.. any observations there?
Not a clone to clone comparison either, but same strains from same seeds.
How about fatter gland heads? I seriously didn't need a scope on a couple of those uv plants.
I switched the uv t5 to a red bloom bulb and moved it down, same cmh main lamp, and the nugs under the red really plumped and hardened a bit extra. I'll stick with that before uv again.