Has anyone experimented with adding UVA and UVB to your spectrum?

Discussion in 'Lighting' started by jawlessbody, Apr 22, 2021.

  1. So. The reason I ask is because I was listening to something with Ed Rosenthal and he indicated that cannabinoid production was linked to UVA light and trichome production is linked to UVB light. Is there a way to incorporate these into an indoor setup without possibly burning the plants? My assumption would be that you would want to keep it proportional to the amount of UVA and UVB in sunlight. Meaning the same percentage of light? I wouldn't even know how to begin calculating that.

    Any help?

    Sent from my LM-V600 using Grasscity Forum mobile app
     
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  2. I have experimented with UV-B lighting .

    Just so you know you add in UV-B lighting to burn your plants in the last two weeks of flowering .
    The million dollar question is how not to burn the to much ..
    The theory is just give the plant a sunburn ..
    I have my UV-B lights set at one minute on every sixty minutes twelve hours a day .
    The so called experts is California Light Works .
    One issue is Sativa burns easier then Indica , I am a Sativa grower .

    I find almost all MJ grow books out dated , and even worse is some are not correct .
    UV-B light will blind you and your pets
     
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  3. Don't have anything on UVA. but I do have one on UVB.

    UV-B radiation effects on photosynthesis, growth and cannabinoid production of two Cannabis sativa chemotypes. (USA) (download – 1987) Cannabis sativa CHEMOTYPES

    Granny :wave:
     
  4. I just added the California Lightworks UV system to my lighting.
    It was on backorder, but they are now in stock.
     
  5. Migro has a y*utube channel where he goes into UVB in great detail, compares lights, how to use, etc.
     
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  6. Here is a pic of the Calif Lightworks UV system installed in my grow chamber.

    I enclosed the CLW 550 because I need to dump heat.

    I adapted my 6" ducting I used for my old CLW 880 which I originally used for my 600watt Cool Tube. DSC_0118.jpeg
     
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  7. Uva over uvb for me
     
  8. Why are you saying UVA over UVB?
     

  9. Woah. Definitely going to look into investing in this for the next flower cycle. Thanks for the tip off!
     
  10. #10 Hybridway, May 3, 2021
    Last edited: May 3, 2021
    I say this for me because I've heard to many horror stories about growers trying to use uvb. It works when done right but why? We were getting higher thc just using leds. Then we got higher then that with a broadband spectrum, targeted spectrum (Broad with peaks). Now we're into uva technology bumping that thc n cannabanoids a Lil more even. Bag appeal inline with good enhanced white leds.
    I choose UVA for its ease & it's what makes the most common sense to me. The sun provides allot of UVA But very little UVB. I still believe that the combination may Trump either or & bars are out now with both. Whether they are proportioned correctly, idk. But they're available.
    UVA also lines up with 660 as in Chlorophyll A.
    Don't get me wrong, one can damage their plant with UVA Too. But it's allot easier not to by knowing how much your fixture provides, then putting it on a timer. I Do this his rather then UVB, which is hitting the top of the plant & damaging the trichomes if not done right.
    A Company called GrowlightsAustralia has been paying close attention to there growers testing & they are seeing N/UVA + UVA beating out UVB in all there tests. Granted I'm a Lil skeptical of how the tests are done but at least it's an effort. I'm a firm believer in tests being done from one person that has identical sbs set up, clone from same mom, ect.. all it takes is for one grower to defoliate, cut leaves, cause a drought environment cycle, ect... to throw things off because any of these causes stress & the plant to produce more trichomes in defense of an animal nibbling on it (cutting leaves or de-do).
    For me it just doesn't make sense because I feel the Con's outweigh the Pro's & one can get the same results or better through other methods. Similar to raising your heat/ambient temps just because the plant may utilize co2 better. Just my take on it. To each his own.
     
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  11. 95% of uv from the sun is uva. 5% is uvb & only 1/3 of both reach us.
     

  12. This is incredible info. Thank you very much! Can you recommend and UVA light or a mixed spectrum UV light to look into?
     
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  13. #13 Hybridway, May 4, 2021
    Last edited: May 4, 2021
    Thanks You, My pleasure.
    I use the Amare Bar-8 HUV & Bar-6 Demo. I have x20 Bar-6 Huvs coming in now. The website will have updated info today or tomorrow. Rather then waiting on the new site they're editing the old for now so you guys can get the 411. 3 channels, veg/bloom/UVA, all on dimmers creating many a spectrum dimming into each other. Uva on timer & dimmer. Broadbanded with Cyan gap filled + ir. Here's the two dimmed. HUV IS in veg mode in pic on low. 20210324_014731.jpg 20210407_001018.jpg 20210407_001035.jpg 20210409_030302.jpg 20210409_030328.jpg
    2.9 umols/j when dimmed to 660w. 2.79 or something close at 900w. Uva decreases electrical efficiency but rarely would you run it full blast &:also on a timer. Increases photosythetic efficiency tho. Bar-8 HUV.
    Bar-6 Demo has x6 uvas & x12 irs on each bar. You may notice others showing a spectral chart showing a similar peak of intensity even know they're using only x3 UVA's per bar. Welp, that's their plan unfortunately. UVA's at 390 are 20,000hr chips. So right when your warrenty runs out, so does your UVA's. Amare ran twice as many at half the current, provided a dimmer & a timer port to get that 50,000hrs. Bonus is complete coverage.
    Beware of those selling boards or bars with just enough Chips to achieve the spectrum & ones with no dimmer or timer.
     

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