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Another debate question for the experts

Hushpuppy

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So I have been doing a lot of reading about lights, and the spectrums of light that plants use. I have read some interesting information that light in the "actinic blue" range(450nm) is good usable light for plants. But an interesting thing with this spectrum, if I understand correctly, is that it has the same properties of inducing the flowering hormone while also feeding chlorophyll energy as well.

I am wondering about using this light along with the HPS, but while the HPS would turn off after 12hrs, the actinics could stay on for another 4hrs to feed the plants and prevent "stretch" without disturbing the flowering light cycle.

I have also read that this can be done with the UV deep blue lighting as well without disturbing the light cycle, but supplying the extra needed energy to prevent "stretch".

Has anyone heard of doing this? Any good or bad results from trying it? I know this gets into splitting hairs with preventing "stretch" and causing "stress". I just like investigating new techniques, and the science of it all fascinates me. :cool:
 

Growdude

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Hushpuppy said:
So I have been doing a lot of reading about lights, and the spectrums of light that plants use. I have read some interesting information that light in the "actinic blue" range(450nm) is good usable light for plants. But an interesting thing with this spectrum, if I understand correctly, is that it has the same properties of inducing the flowering hormone while also feeding chlorophyll energy as well.
Gotta link to what you read? never heard of this before. thxs
 

Hamster Lewis

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Yes a link wld be most excellent...sounds like interesting stuff.
 

mr_chow

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blue spectrum lighting during veg is most beneficial for short internodal lengths and propagation of females...i've read this before.

...red spectrum lighting is supposed to be beneficial for flower growth.


i had a couple of hydrofarm 400w MH lamps with bulbs that were supposed to have more red spectrum than other MH bulbs...used them throughout the whole grow w/o switching. had some good results...but never did any comparative testing.
 

Growdude

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mr_chow said:
blue spectrum lighting during veg is most beneficial for short internodal lengths and propagation of females...i've read this before.

...red spectrum lighting is supposed to be beneficial for flower growth.


i had a couple of hydrofarm 400w MH lamps with bulbs that were supposed to have more red spectrum than other MH bulbs...used them throughout the whole grow w/o switching. had some good results...but never did any comparative testing.
This we know. Its the blue light that wont interupt flower part ive not heard of.
 

Sol

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What is the 'UV deep blue spectrum'? Is that the proper name for the ultra voilet light that we all know of in everyday applications or is it just part of the standard blue spectrum that we try to recreate with artificial lighting specially for plants.
In short, i'm asking would this source of light come from a UV bulb or an HID with enhanced blue spectrum? That makes more sense ,right?
 

mr_chow

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Growdude said:
This we know. Its the blue light that wont interupt flower part ive not heard of.

ah, just reread the post. interesting.

...i only thought green-light would not disturb flower, but now thinking about it, how would cannabis flower in the artic w/o being disturbed by the 24-hrs of light??


hmmm, interesting topic, for sure. i'm in...
 

mr_chow

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wanna know the "truth", you gotta go to the experts

hxxp//mjgrowers.com/book_what_exper1.htm
GREEN AND BLUE LIGHT AT NIGHT (by Ed Rosenthal)
As plants evolved for hundreds of millions of years they never actually had to deal with separation of light spectrums or unusual lighting regimes. When they received light it came from the sun in a mixture of spectrums and they could pick and choose which to use. It was only with the advent first of gas and then electric lighting that plants encountered unusual regimens and splintered spectrums.
Plants measure day length using the red light spectrum. While they use other spectrums for other purposes, they are not sensitive to them as far as flowering is concerned. They are almost totally insensitive to green light and for this reason reflect it back to us while absorbing most other spectrums.
Plants’ insensitivity to green light can be used to a gardener’s advantage. You know that turning the light on in the middle of the dark cycle disturbs the plants’ flowering paradigm. The light, HPS, fluorescent and MH lamps all emit red light. Green fluorescent and LED lights contain no red light and will not disturb the dark period. You can go in the garden under adequate light to work, as long as it is green.
Plants use blue light for certain regulatory processes and also for photosynthesis. Chlorophyll absorbs both blue and red light and uses the light’s energy to power the complex process in which water and atmospheric carbon dioxide are converted to sugar and oxygen gas. Blue light does not affect the regulation of flowering.
When blue light is turned on during the dark period, plants photosynthesize but their flowering isn’t affected. This results in more growth as the plants produce more sugars. Before LED lights it was difficult to create a pure blue light. Instead, most of the time other spectrums were filtered out, which can be an inconvenient process. Try using between 20 and 40 watts of mixed blue light per 1000 watts of regular light. I have done only initial experimentation with this so test this in a limited way first. I suspect that the additional light is an efficient way of increasing total yield
Aside from red and blue light, plants also use orange light for photosynthesis. I haven’t experimented with them yet, but orange LEDs might also help increase yield and probably can be lit continuously, just like the blues. More on this as the news breaks—or at least, as it fractures.
 

stevetberry

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I am on my 8th grow and I have a constant monitoring meter that has a blue display and it has not caused any problems. I also go into my grow room at least 4 or 5 times during the dark period per day using a green LED flashlight and have had no problems. A little off subject but I have seen many posts telling not to interupt the dark cycle but it can be done with care.
 

Growdude

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stevetberry said:
I am on my 8th grow and I have a constant monitoring meter that has a blue display and it has not caused any problems. I also go into my grow room at least 4 or 5 times during the dark period per day using a green LED flashlight and have had no problems. A little off subject but I have seen many posts telling not to interupt the dark cycle but it can be done with care.
Why would you need to go in your gow 4 or 5 times a night?

Thxs Mr Chow for the read.
 

bho_expertz

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Anyone knows which equipment gives just blue spectrum ? Any links ? Thanks.
This is good stuff :aok:
 

BBFan

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Interesting read. Thanks for the post mr chow. Does anyone know anything about these lights that produce only true blue light in the right spectrum?
 

nouvellechef

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Kool new stuff. But have no idea why you would need to be in the garden at lights out. Now, if it increased resin production or yield. I am down with it. Other than that. I do like keeping girls up all night, but girls need sleep too.
 

mr_chow

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at the last kushcon there were some fools selling some led lighting...hempcon is coming up so i'll ask around. ...will let you know if i find out anything.



peace,

mr_chow
 

Hushpuppy

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Sorry to take so long to get back to everyone here. had to go out of town. I don't have a link for the information. I read it in my books from Ed Rosenthal and Greg Green. I saw some bulbs online called "actinic" which are supposed to emit light specifically at 400-450nm, which according to the books is at the level that gives light energy to the plants for photosynthesis but doesn't interfere with the photocycle. :)

Here is a link to the T5 actinic light: hxxp://www.specialty-lights.com/531060.html

The UV deep blue is another light that I saw online that emits only UVB light and appears deep blue, almost like a "black light". unfortunately, I don't remember where I saw it.
 

Hushpuppy

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Solanero said:
What is the 'UV deep blue spectrum'? Is that the proper name for the ultra voilet light that we all know of in everyday applications or is it just part of the standard blue spectrum that we try to recreate with artificial lighting specially for plants.
In short, i'm asking would this source of light come from a UV bulb or an HID with enhanced blue spectrum? That makes more sense ,right?
Yes the UV is the ultraviolet lights. There are 2 types, UVA and UVB, that are becomeing well known because of tanning, sunburn, and sunglass issues. I can't remember where I read it but there was something said about UV light have the property of positively effecting the flowering while also still supplying considerable photo energy.:)

I think the actinic bulbs don't emit so much of the UV light but more specifically the 420nm wavelength of regular light, which I think is just below the UV range. It is still in the visible spectrum I believe.
 

BBFan

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Hushpuppy said:
Yes the UV is the ultraviolet lights. There are 2 types, UVA and UVB, that are becomeing well known because of tanning, sunburn, and sunglass issues. I can't remember where I read it but there was something said about UV light have the property of positively effecting the flowering while also still supplying considerable photo energy.:)

I think the actinic bulbs don't emit so much of the UV light but more specifically the 420nm wavelength of regular light, which I think is just below the UV range. It is still in the visible spectrum I believe.
Actually there are 3 types UVA, UVB, and UVC. Clarke, in MJ Botany, discusses the role of UVB lighting and it's effects on the metabolic pathways of thc. I've never seen anything written or discussed whereby it positively affects flowering. There has been much debate on whether UVB influences the production of trichomes as a defense mechanism.
 

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