Need help with UV question

You have been growing for 4 years now, why are you asking questions if you know everything anyhow?

'field' studies means out in a field.. lol... not a field of biology or used in a different way. out under the sun... and the plants likely grew resitant to it by maturity, which is probably why those early studies showed it was useless... and also a good example of why you need several studies to be certain about anything.... not to mention the bulk of research is a bit sketchy to start, lol. Always remember that initial studies are 90% proven false with further study. Unless it is very cut and dry hypothesis being tested, never trust initial studies. Some things are so simple that you can be fairly certain, but most contexts are not.

lol, okay? we don't interract much, i'd be curious how that happens.. not that i mind. Evidence for UV is a maybe. Field studies showed it was useless, but indoor studies recently by bugbee said it was a maybe, i.e. inconclusive with limited study or too small of an effect to discern from normal volatility of control group. Scientfic method is not absolute from 1 study. must be repeated and the methods need to be peer-reviewed or you end up with that 11-person study showing vaccines cause autism, which was total nonsense because the 'scientist' that run that experiement cherry picked and put his finger on the scale. i don't know th umol/s per sq ft to apply, but i do know if it works you want to just apply the minimum damage per day and turn them off. Also, only useful when the capitulated trichomes are starting to form.. probably want to pre-empt that to be safe. Don't use it in vege. That is why the field crops showed it was useless in studies back in 1970s or whenever it was done. The plants will adapt and develop resistance to UV over time. So... it may be reaosnable to slowly apply a bit more umol/s per day over time... but that's just an educated guess. UV is incredilby bad for humans. Definitely have an off switch before you enter your tent. You do not want to be consistently exposed to UV I can understand if someoen would not want to take a risk for a potentially small effect on the outcome. Stil possible it doesn't even do anything useful. Unless there are several studies by different researchers and you make sure their methodology isn't total trash, then you can trust it as fact. if you don't know how to weed out bad methodology, there's a shit ton of bad research out tehr (See the autism example above) because it's more important to be published than to publish good work. Scientific research is not perfect nor pure, but if you know how to weed out the stupid shit, it's 10,000x better than anecdotal knowledge. Also, UV does not power photosynthesis. UV is approx. 10-400 nm wavelengths, even the proposed ePAR (380-750) barely overlaps and PAR wavelength range not at all. 380-750 nm. If it has any influence on photosynthesis it's so small that it is irrelevant. So again, don't bother using in vege phase as it's probably useless and just allowing the plant to develop resistence to it, which would reduce any potential impact. not sure why greenclaws has a bug up his ass about me. I give evidence based answers. I can provide source material for most of anything i say. Not some bro science bullshit from forums and hs-educated anecdotes. I 've taken plant bioloft / microbiology / organic chemistry / physics / calculus etc.. i actually am qualified to talk about a lot of this stuff in a fairly sophisticated way. My Masters degree is not in the sciences, but i enjoyed the sceinces enough to take a bunch of extra credits while i was in school. computer programming and finance actually help quite a bit too, indirectly.

https://www.solacure.com/myths.html Read this before spouting out all your scientific bs. The author has 27 years working with UV. At least half of it dedicated to weed. He explains in simple terms.

WATCH THIS SPACE

tense... agreed lol

Answering ?s is a little tense today! How many of you cut and paste encyclopedias actually have experience with UVB? Pretty sure the guy wants actual users opinions.

There are probably a lot more aspects that growers need to get right before thinking of trying additional uv lights. Iv done a little bit of reading up on the different supplement UV lights that can be added into grows but I don't feel the extra cost is worth it. It would be good to see some controlled experiments with clones to see what the UV supplements really do.

Is Alien being funny// whats up pal/ explain yourself please... much love

i cant read and wont read his nonsense... you know your stuff UV... if he wants to read about growing while we find the best way to do it... leavce him behind... bye bye 10101010101

@m0use, this is not correct - the ozone layer with respect to Earth's atmospheric composition has been repaired other than a singular hole (usually overtop an ocean) which was observed prior to the degradation caused by humans altering the atmosphere's composition; I am correcting you not to be pedantic but arguably this is one of humanity's greatest achievements where populations and world governments all adhered to physicists and scientists for the betterment of our species.... it should be given the respect it is due. can you even fathom that type of cooperation today? I think what you are referring to is the IR window in the EM spectrum, which WAS a key part of Earth's atmospheric properties. This is the underlying mechanism for the overall increase in unpredictability of weather phenomenon at the local scale and increasing temperatures on the global scale - because we flooded our atmosphere with particles that conveniently are the perfect size to absorb all that yummy IR energy. That is basically ""climate change"" with no political spin - pure math and physics. Like, I don't know how to really reduce that any further but by example - the only other 'window' in the spectrum is the visible light window..............if that closed, as the IR window is closing, then we would literally not see colors on our planet anymore. So, yeah, the physics are REALLY definitive here. My academic disposition, not my self-educated opinion, with respect to UV light in the cultivation of cannabis is that it has been shown to nominally increase terpene and flavonoid production, with little impact on cannabinoid mass. In my personal experience (I do UV-A supplemented grows just to point to for questions like this) UV light changes the location of where the plant deposits first, as a manner of protecting the most vulnerable places (like fringes or leaf tips). I only use UV-A, B and particularly C wavelength are bad for biological matter (the same mechanism as the IR window closing, here the conveniently sized particle is your DNA which gets hit like a projectile by the photon). UV-A is relatively safe to work with. I still turn my ;lights off if I am going to be exposed for any significant duration. At the end of the day, there is not much use for it IMO - it is simply a less efficient source of energy for the plant at the most basic level. Just like green lights, you're harming more than helping. I think boards should have an array of UV diodes of course but growers should not be supplementing any phase with dedicated UV unless they have temp/humidity/pest issues. You certainly can do it, but just like with CO2 supplementing....99 out of 100 people doing it are doing it completely wrong. I have applied UV-A during dry at times in the past. THC degradation from UV light is minimal with UV-A, only impacts the surface, and you're most likely to just create an isomer than destroy it (worst case impacting potency +/-10%). Either way, intermittent UV-A on drying flower is a sound practice if you need the pathogen mitigation from a physics standpoint.

hey i have an idea, why don't the bunch of you who seem to use this platform for your own immature and and childish playground go find someplace to play around. thank you

Forgot to show how I break up the timer to get my exposure levels. Disregard week/day and use it to adjust your own timer. I have a dedicated timer for my UVB lights. UVB Exposure Wk 19, Day 1 start UVB between 10am - 3 pm @ 15 minutes on the hour. (1½ hours total exposure). Wk 19, Day 4 footprint: 10 am @ 30 minutes; 12 pm @45 minutes; 2 pm @ 30 minutes. (1¾ hours total exposure). Wk 20 Day 1 footprint: 9 am @ 15 minutes; 10 am @ 30 minutes; 12 pm @ 45 Minutes; 2 pm @ 30 minutes; 3 pm @ 15 minutes. (2¼ hours total exposure). Wk 21 Day 1 continue wk 20 footprint.

UVB incorporated into my garden since '23. Some improvement but not like the hype. Trichomes production did increase but not to the extent the hype professes. Look at it as if you're growing under the sun in nature. In nature UVB causes marijuana to produce trichomes in an attempt to provide sunscreen from its effects. Here is my UVB schedule and my personal reference links. Gives you a good idea how UVB works. Lattitude and Altitude also play a part in intensity. UVB Setting This Grow* ** Wks 4 - 5 of flower UVB introduced*** @ 15 minutes on the hour between 10am - 3pm. (1½ hours total exposure). Introduction begins when lights mount directly to crossbars using carbiner clips. UVB this setting continues through harvest. Wk 5 increase to 1¾ exposure. Wk 6 increase to 2¼ exposure until harvest. * “(https://www.epa.gov/radtown/ultraviolet-uv-radiation-and-sun-exposure#about-ultraviolet-radiation-and-sun-exposure) In nature peak UVB hours are between 10am and 4pm.” Intensity is latitude & altitude dependent. ** “Solacure (https://www.solacure.com/myths.html); Busting common myths about cannabis and UV." UVB decreases exposure due to sun's angle during this time. Plants receive UV exposure during the whole flower cycle. “https://www.solacure.com/stress.html#:~:text=Low%20level%20continuous%20UVB.,against%20mildew%2C%20mold%20and%20insects.” Plants receive UV exposure during the whole flower cycle. “https://californialightworks.com/blog/uvb-light-and-thc-potency/ .“ UVB Light And Boosting THC Potency “https://californialightworks.com/blog/what-is-the-best-led-spectrum-for-growing/” well constructed article regarding growing under spectrum controlled lighting. Hope it helps. You can msg me if you need more.

I don't like it because I don't need to be exposing myself to more UV then I already do. Plus their did not used to be any or very little UVB and UVC before when the Ozone was working correctly. So avoid all b and c rays. they bad news bears... yea know.

with the name of "Ultraviolet" I think it would be clear.