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Thread: UVB/Cannabis science report

  1. #21

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    I use mine as a supplement whenever my HPS is on. But scientists used it, quoting: "Ultraviolet-B radiation was provided for 3h on either side of solar noon". Does this mean that they had it on 6 hours a day then? Like from 9 am - 3 pm, and solar noon is at 12? Not soo good at these english time standards..

    Regarding the reflector for UVB.. i should look over mine then, a home made reflector for the UV light, maybe not so good if it creates hotspots with UV... However, my UV is very weak, only 13w
    Last edited by Tetra; 11-02-09 at 04:21 PM.

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  3. #22

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    Ohh! I just found these 26w Repti glo 10.0 for about $23 USD on the net. Ordered 2 of them directly. Now they gonna get some real deal UV-B the last 4 weeks of flowering! Just have to get a separate timer for those..

  4. #23

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    A friend of mine has his UV's on 12/12 with no noticable problems though

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  6. #24

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    Quote Originally Posted by Tetrahydrocanna View Post
    I use mine as a supplement whenever my HPS is on. But scientists used it, quoting: "Ultraviolet-B radiation was provided for 3h on either side of solar noon". Does this mean that they had it on 6 hours a day then? Like from 9 am - 3 pm, and solar noon is at 12? Not soo good at these english time standards..

    Regarding the reflector for UVB.. i should look over mine then, a home made reflector for the UV light, maybe not so good if it creates hotspots with UV... However, my UV is very weak, only 13w
    The time variations people were using them for depended on whether it was a 26w cfl type or the much bigger 160w plus Mercury Vapour type as well as the ancestry and genetics of the plant with Sativas having a natural inclination to deal with more intense UVB for longer periods

    Regarding reflectors, plain shiny aluminium will reflect it at too high an intensity and these lamps are more often used in a white coated/painted reflector, often ceramic dome type, there's a suitable clip on dome type at a reasonable price for the 26w cfls on a well known online auction site, they are normally quite pricey.
    Last edited by Nephilim; 11-02-09 at 06:15 PM.

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  8. #25

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    Well, in the report they used totally 240w UV-B with good results, but i imagine they had a rather big area to cover, at least 5 m2 to get down to 72w/m2 wich i estimate is around 14 kJ/m2 wich is their recomendation. 3x26w should cover 1m2 i think But i may be wrong in my estimates

    I will change my reflector then, maybe just get a simple white paper on wellpap to get a little reflection. The new wones will be hangin along mylar walls so they reflect good. I think that will be fine

  9. #26

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    Quote Originally Posted by Nephilim View Post
    Sativas having a natural inclination to deal with more intense UVB for longer periods
    I think any plant capable of producing high amounts of THC resist UV-B light splendidly, and is able to adjust it levels of UV-B absorbing THC to match the amount of UV-B present in environment it's in. It's only the Fiber-plant, non-thc producing plant that cant do this. But according to scientists in the report, these did not get harmed by the high amount of UV-B (similar to 3000m mountains). But the scientists theorized that there was some other UV-B absorbing metabolites as well, that these plants used, flavonides and such. But i guess, to high amounts of UV-B and these plants would get more damaged than the high THC producing. According to theories in the article, the high mountain THC producing cannabis, has had better reproducing abilities due to the THC protecting the calyx, and is therefore spread in these areas. And as you know, the trichomes with high amount of THC thrive on calyxes. So imho, and the researchers as well, any Drug-type cannabis will benefit from UV-B light, and in their trials none of the two chemotypes was harmed.

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  11. #27

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    Quote Originally Posted by Tetrahydrocanna View Post
    I think any plant capable of producing high amounts of THC resist UV-B light splendidly, and is able to adjust it levels of UV-B absorbing THC to match the amount of UV-B present in environment it's in. It's only the Fiber-plant, non-thc producing plant that cant do this. But according to scientists in the report, these did not get harmed by the high amount of UV-B (similar to 3000m mountains). But the scientists theorized that there was some other UV-B absorbing metabolites as well, that these plants used, flavonides and such. But i guess, to high amounts of UV-B and these plants would get more damaged than the high THC producing. According to theories in the article, the high mountain THC producing cannabis, has had better reproducing abilities due to the THC protecting the calyx, and is therefore spread in these areas. And as you know, the trichomes with high amount of THC thrive on calyxes. So imho, and the researchers as well, any Drug-type cannabis will benefit from UV-B light, and in their trials none of the two chemotypes was harmed.
    The damage I saw pictured in test grows was reckoned to be caused by having light too close, there is a lot of info online on the dangers of having these lamps too close or on too long for reptiles and how some types/makes of bulb produce ludicrous amounts of UVB at close distances. I guess I just tend to err on the side of caution, I know plants and reptiles are very different, lizards make a mess of your grinder.

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  13. #28

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    Yes, also read that some of these types of UVB lights, especially the CFL-ones can be harmful to reptiles, due to the low band UVB radiation, however, thats good for cannabis Haha, yes i bet a lizzard is bad for the grinder.. if not the least, the grinder is bad for the lizzard :P

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  15. #29

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    One things for certain, it's not good for us so anyone considering using UVB, BE SAFE and get eye protection and cover up. You can be super safe and look cool too lol

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  17. #30

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    Yes, recomend treating the bulbs as if their radioactive, it's def. comrpairable! I use gloves, and sun glasses when reachin in to to turn it off.

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