the HPS bulBS mimic the sunset when they turn on and off, they throw out low frequency(415nm+) light when turning on and glowing from being on, when turned off.flavoraid said:
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UVB bulbs...
- Thread starter dontstepongrass
- Start date
I was trained as a plant scientist and worked with the discoverer of cryptochrome (the "blue light receptor" molecule in plants), so i can address some of you "scientific" concerns.....
For a long time scientists thought there was only one light-receptor molecule in plants which they call "phytochrome"......it took a long time for them to accept the fact that another receptor exists which was named "cryptochrome," because it was so "cryptic" that it eluded scientific discovery for such a long time......so, nowadays, scientists theorize that there are a few other receptor molecules that have yet to be discovered......these include receptors for green light, far-red light, and even one for UV-A and UV-B light......
Phytochrome (the red-light receptor) absorbs light at a wavelength of 660 nanometers......its true that HPS lights do imitate the rising and setting sun, where red-light is more visible to the human eye, but plants are always able to absorb red light no matter which hour they receive it......
Cryptochrome (the blue-light receptor) absorbs light at a wavelenght of 420 nanometers......the MH bulbs produce blue light most effectively......
So now you see why growers like to mix HPS and MH bulbs......one targets the red-light receptor and the second targets the blue-light receptor......
I have not performed experiments exploring the effects of UV-B light on cannabis plants, so the best i can do is to refer you to the "Marijuana Optics" paper and the "THC UVB and Me" video on Youtube......
Just be careful with UVB because long-term exposure can lead to skin cancer....
kind regards from guineapig
For a long time scientists thought there was only one light-receptor molecule in plants which they call "phytochrome"......it took a long time for them to accept the fact that another receptor exists which was named "cryptochrome," because it was so "cryptic" that it eluded scientific discovery for such a long time......so, nowadays, scientists theorize that there are a few other receptor molecules that have yet to be discovered......these include receptors for green light, far-red light, and even one for UV-A and UV-B light......
Phytochrome (the red-light receptor) absorbs light at a wavelength of 660 nanometers......its true that HPS lights do imitate the rising and setting sun, where red-light is more visible to the human eye, but plants are always able to absorb red light no matter which hour they receive it......
Cryptochrome (the blue-light receptor) absorbs light at a wavelenght of 420 nanometers......the MH bulbs produce blue light most effectively......
So now you see why growers like to mix HPS and MH bulbs......one targets the red-light receptor and the second targets the blue-light receptor......
I have not performed experiments exploring the effects of UV-B light on cannabis plants, so the best i can do is to refer you to the "Marijuana Optics" paper and the "THC UVB and Me" video on Youtube......
Just be careful with UVB because long-term exposure can lead to skin cancer....
kind regards from guineapig 
guineapig said:I was trained as a plant scientist and worked with the discoverer of cryptochrome (the "blue light receptor" molecule in plants), so i can address some of you "scientific" concerns.....
For a long time scientists thought there was only one light-receptor molecule in plants which they call "phytochrome"......it took a long time for them to accept the fact that another receptor exists which was named "cryptochrome," because it was so "cryptic" that it eluded scientific discovery for such a long time......so, nowadays, scientists theorize that there are a few other receptor molecules that have yet to be discovered......these include receptors for green light, far-red light, and even one for UV-A and UV-B light......
Phytochrome (the red-light receptor) absorbs light at a wavelength of 660 nanometers......its true that HPS lights do imitate the rising and setting sun, where red-light is more visible to the human eye, but plants are always able to absorb red light no matter which hour they receive it......
Cryptochrome (the blue-light receptor) absorbs light at a wavelenght of 420 nanometers......the MH bulbs produce blue light most effectively......
So now you see why growers like to mix HPS and MH bulbs......one targets the red-light receptor and the second targets the blue-light receptor......
I have not performed experiments exploring the effects of UV-B light on cannabis plants, so the best i can do is to refer you to the "Marijuana Optics" paper and the "THC UVB and Me" video on Youtube......
Just be careful with UVB because long-term exposure can lead to skin cancer....
Here is another link to add to your reference list Guineapig and all else who have understanding.
"The Chemical Ecology of Cannabis" - Pate
http://www.hempfood.com/Iha/iha01201.html
Namaste, mess
l33t said:
I thought so, too. But if you liked that one, you'll love this one. A voluminous tome and it is a bit dated (1994), but it has a wealth of info still relevant. I printed out every last page and often read through a study or an article when in the "library."
International Lighting in Controlled Environments Workshop:
http://ncr101.montana.edu/Light1994Conf/index.htm
Namaste, mess
thank you guys! some good info here... will take a bit to sort through it all
Thanks again mess'n'gommin'
Its looks a long read ..but I always like to read technical stuff! I think I ll print it out too so its easier to read.
Btw I would like to say that I believe that even if we use UV supplemental lighting indoors of the correct 'intensity' and spectrum the results still may not be the same (as outdoors) as the light rays emitted from bulbs are not parallel like in the case of the sunlight. Just a thought
Thanks very much again for the links.
Its looks a long read ..but I always like to read technical stuff! I think I ll print it out too so its easier to read.
Btw I would like to say that I believe that even if we use UV supplemental lighting indoors of the correct 'intensity' and spectrum the results still may not be the same (as outdoors) as the light rays emitted from bulbs are not parallel like in the case of the sunlight. Just a thought
Thanks very much again for the links.
from marijuana man (and i quote): "we ain't gettin' fuckin stoned off the leaf!"
exactlydontstepongrass said:
not really, sorry, i can tell you there in a yellow spectrum though..flavoraid said:
guineapig- thanks for that info, its nice getting the technical break-down, its been a while since bio class......
SuperToker
Member
No pet store light is going to be nearly as good as a real HPS grow light. Don't mess with the t5 lights, you're wasting your money. Get a real HPS ballast, lamp, and reflector. 400w will get you started.
were talking about supplementing light using a t5 ballast and putting in a uvb light.
guiena said this "AND '120W Clear Incandescent bulb as well for 1 hour either side of lights on and off - simulating the red ambient light of the outdoors ever dusk and dawn of every day anywhere in the world'."
guiena said this "AND '120W Clear Incandescent bulb as well for 1 hour either side of lights on and off - simulating the red ambient light of the outdoors ever dusk and dawn of every day anywhere in the world'."
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this is turning out to be a decent thread. let's keep the info coming guys. any more people out there with experience with these?
after watching the youtube vid i am determined to try it myself. a situation he described was a 400 watt grow supplemented with 1 uvb light on for 5 hours in the middle of the day cycle. he said that same strain with uvb was "up a couple notches" from that strain without uvb.
but apparently you can play around with the hours and if you wanted uvb could be on 24/0 and plants would still flower.
i wish to utilize
after watching the youtube vid i am determined to try it myself. a situation he described was a 400 watt grow supplemented with 1 uvb light on for 5 hours in the middle of the day cycle. he said that same strain with uvb was "up a couple notches" from that strain without uvb.
but apparently you can play around with the hours and if you wanted uvb could be on 24/0 and plants would still flower.
i wish to utilize
The youtube vid was cool.
Stay up MJman.
Stay up MJman.
G
Guest
UV LEDs aren't really UV, they are near-UV, a violet colour. CREE, Edison Opto, LEDengin, Prolight, Winger, they all make high power UV LEDs, but they are 390-410nm, and UV-A is 320 to 380nm. True UV LEDS below 380nm are available, 375nm and 365nm wavelengths being the most common, but they are very expensive, 100 bucks for a high power one.
I managed to find a 380nm 5mm LEDs very cheap and have constructed several 60-LED panels using them and am about to begin UV experiments.
I've also purchased some 390-410nm Edison Opto 3W UV LEDS and will add those shortly.
The far-red thing is quite simple, durign the day, a substance called phytochrome-r (r for red) is produced by the plant in response to 600nm red light. After the daylight has gone, this phytochrome-r is converted into phytochrome-fr (fr for far-red) in response to 735nm radiation. When all the phytochrome-r has been converted back into phytochrome-fr, the plant will flower, this is how plants determine the daylength, so you can see how 660 and 735nm light is essential for flowering plants. It has been shown that you can force phytochrome-r back into phytochrome-fr by blasting the plants with lots of 735nm light at the end of the light period, so in theory, you could flower the plants with 16-18 hours of light per day and blasting them with 735nm light for the other 6-8 hours, in effect trickignthe plant into thinkign the critical daylength has been reached. This has yet to be demonstrated with cannabis though and 735nm LEDs are rare and damn expensive, Roithner do one but it's over 120 dollars, Epitex make a 735nm 4.2W LED but it's also over 120 dollars. The remaining option is the Edison Opto 730nm near-ir 3W LED, but so far I've not found a supplier of these. The advantage of being able to flower with 16-18 hours light is thast you are pumping 25-30% more photonic energy into the plant, resutling in larger yields and perhaps shorter flowering times.
Until someone can demonstrate the benefits of UV on resin production and psychoactivity, I remain sceptical. Yes, the hard science has been done, but no-one has publicly demonstrated the effects of UV on flowering cannabis indoors.
I'm not sceptical about the use of 735nm light for phytochrome forcing, but until the far-red LEDs are widely and cheaply available, no further practical experimentation can be easily done.
I managed to find a 380nm 5mm LEDs very cheap and have constructed several 60-LED panels using them and am about to begin UV experiments.
I've also purchased some 390-410nm Edison Opto 3W UV LEDS and will add those shortly.
The far-red thing is quite simple, durign the day, a substance called phytochrome-r (r for red) is produced by the plant in response to 600nm red light. After the daylight has gone, this phytochrome-r is converted into phytochrome-fr (fr for far-red) in response to 735nm radiation. When all the phytochrome-r has been converted back into phytochrome-fr, the plant will flower, this is how plants determine the daylength, so you can see how 660 and 735nm light is essential for flowering plants. It has been shown that you can force phytochrome-r back into phytochrome-fr by blasting the plants with lots of 735nm light at the end of the light period, so in theory, you could flower the plants with 16-18 hours of light per day and blasting them with 735nm light for the other 6-8 hours, in effect trickignthe plant into thinkign the critical daylength has been reached. This has yet to be demonstrated with cannabis though and 735nm LEDs are rare and damn expensive, Roithner do one but it's over 120 dollars, Epitex make a 735nm 4.2W LED but it's also over 120 dollars. The remaining option is the Edison Opto 730nm near-ir 3W LED, but so far I've not found a supplier of these. The advantage of being able to flower with 16-18 hours light is thast you are pumping 25-30% more photonic energy into the plant, resutling in larger yields and perhaps shorter flowering times.
Until someone can demonstrate the benefits of UV on resin production and psychoactivity, I remain sceptical. Yes, the hard science has been done, but no-one has publicly demonstrated the effects of UV on flowering cannabis indoors.
I'm not sceptical about the use of 735nm light for phytochrome forcing, but until the far-red LEDs are widely and cheaply available, no further practical experimentation can be easily done.
I think that that is where a lot of the controversy comes from. The function of the cryptochromes are not nearly as well understood as the phytochromes. From all that I can find about the UVR spectrum says that, for the most part, UVA is thought to enhance the flavonoids at a peak of about 390nm's and the "enhancement" of THC production is thought to occur at about 310nm's. In experiments with tomatoes and cucumbers, an irradiance that included UVA made a marked increase in flavonoid production and the conventional wisdom, at least to date, is that the THC increase is due to some kind of self-defense mechanism for protection against the deleterious effects of the UVB spectrum. That may be why some who have used UVB to increase potency have said that too much of it will explode the trichome heads.
Namaste, mess
Namaste, mess
uv bulb emits so few UVB lights that if put close to an HPS almost all of the UVB will be lost due to destructive interference.
It's different matter if you use a UVB bulb with a neon.... they are on the same phase (or slightly shifted) so a very tiny amount of uvb will be lost.
Maybe this is why stoners don't usually notice any difference (it has largely been stated on OG that UVB lights are pretty useless).
If you want an HID with UVBs, then use CMH.
If you want stronger buds, then use the 40$ for an additional 150 W HID lamp, and use the additional weed to make some oil and coat the bud with it.
It's different matter if you use a UVB bulb with a neon.... they are on the same phase (or slightly shifted) so a very tiny amount of uvb will be lost.
Maybe this is why stoners don't usually notice any difference (it has largely been stated on OG that UVB lights are pretty useless).
If you want an HID with UVBs, then use CMH.
If you want stronger buds, then use the 40$ for an additional 150 W HID lamp, and use the additional weed to make some oil and coat the bud with it.
why would someone do that?
were talking about scientifically mimicing the best of nature and beyond and you just try to shun the topic by saying something stupid
"If you want stronger buds, then use the 40$ for an additional 150 W HID lamp, and use the additional weed to make some oil and coat the bud with it."
were talking about scientifically mimicing the best of nature and beyond and you just try to shun the topic by saying something stupid
"If you want stronger buds, then use the 40$ for an additional 150 W HID lamp, and use the additional weed to make some oil and coat the bud with it."
