Green light; officially not safe for light out viewing?

Father Ramirez

Father Ramirez

Well-Known Member
What do you make of this, debunking the accepted belief that a green light is safe during lights out?

From Heliospectra, a commercial lighting company catering to mainstream producers.
"...the entire light spectrum is used to drive photosynthesis. It appears as though green
light is not a safe light and that green light is required for optimum whole plant
photosynthesis. ...."

The full article is here
http://www.heliospectra.com/sites/www.heliospectra.com/files/field_page_attachments/what_light_do_plants_need_2012-10-05.pdf
 
T

Truckstop13

Member
Without reading the article in it's entirety(too many big words) All I have to say is that the green lights used in the grow ops I work at have not effected the outcome of the grows in any noticeable way. Not one hermied plant with every yield in the 1.5p per light range. The green lights are on quite a bit, hours at a time. I'm not saying that in a lab environment subtle changes won't be detected, but after watching successful grow after successful grow with the use of green lights during dark hours, it's hard to believe that there are tangible effects.
 
hyroot

hyroot

Well-Known Member
Plants absorb and reflect green light. Green light drives photosynthesis by helping the plant use all its pigments to absorb more photons in other regions. Plants absorb about 20% - 30% of green light. It would be stupid to use a green light or any light during lights out. It causes stress. Wonder where those few seeds came from on smaller buds. or stunted yield. Excessive green lighting. Its just like hydro shops to sell you stuff that's bad for your garden or stuff you don't need or want.... So you will go back and spend more money... that's capitalism for ya.

here is link to a university study from Oxford University.

http://pcp.oxfordjournals.org/content/50/4/684.abstract
 
Crispy Bacon

Crispy Bacon

Member
if this is true im going to go smash all of mine into bits


What about using them periodically during lights out? Because like truck stop said, I'm yet to see any ill-effects from using them...
 
Bugeye

Bugeye

Well-Known Member
I have three 15 watt green cfls in my greenhouse and only use them for brief periods when something has to be dealt with at night. Probably used less than an hour during all of flowering. Never had any issues but will be extra careful to limit their use after learning this!
 
Nizza

Nizza

Well-Known Member
this is ed rosenthals take on green and blue light at night
"GREEN AND BLUE LIGHT AT NIGHT
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."
taken from this article http://mjgrowers.com/book_what_exper1.htm

what i gather from it, is he is still experimenting and there is no final ultimate conclusion on how these light colors effect plants during dark hours, only a few small conclusions
 
hyroot

hyroot

Well-Known Member
^^^^^^^ since writing that book and helping develop led's if you seen his speech about led's. He did a 180 on that said that leds' are missing green light until they have that they will suffer in yield....not exact words.... Alot of the older growers logic way back when do not hold up any more. They even thought soil is trash when a plant is done. That couldn't be further from the truth.
 
Father Ramirez

Father Ramirez

Well-Known Member
Study aside, to our contributors who have claimed green lights created no ill effects on their plants... I believe you. The whole 'no light leaks' commandment is over-stated. Reality suggests that a short period of light, even repeated, and regardless of spectrum, will have little, in any, effect on our produce of choice. Visit your plants as you need, but be brief and keep the light low. I use a red head lamp discreetly. I have not seen a problem. I simply wanted to share this article and hear the community's opinion. I stand supported, it seems. Thanks for chiming in.
 
a mongo frog

a mongo frog

Well-Known Member
i use my green led lights to work in the dark often. probably 15 hours in 8 weeks. there awesome and nothing bad will ever happen to the plants. only good things.
 
hyroot

hyroot

Well-Known Member
A positive difference, yield, potency, color, flavor, trichome development, etc... Any of those. Not saying all will happen. Any stress is no good during 12/12. You go any where in nature where there's no city lights. Its pitch black at night. Except when a full moon is around and
thats usually the harvest moon at that time.

I personally do all natural living organics. I try to recreate nature. There's no green lights in a forest in night. Except in Alaska and canada. Its usually snow every where at that point. ( northern lights aurora borealis)
 
S

Sticky760

Well-Known Member
Green lights don't work sadly. At least my belief cause if you look under a nanometer chart plants uptake green light even in small amounts. So if that light comes on at night it interrupts the dark cycle. Pretty sure that's why my last crop hermied.
 
J

joe macclennan

Well-Known Member
I don't know why anyone would leave a green light or any light on in their flower room anyway?

getcha a miners light and wear it when you need to go in.

Mines green but after reading hyroots link I think i'll just use my regular white one if need be.

a little light occaisonally won't hurt anything. Hell the moon gets really bright once a month. Like someone else posted sometimes you could read by it.

it's a little light every day when things start to go wrong.
 
hyroot

hyroot

Well-Known Member
During veg its fine I'm sure. Its just during flower . For hermies it can happen if its been multiple times. Imo hermies are causes by unstable genetics or too much red light when they are young. Stress via green light is suffered yield, lower quality, stress seeds (no male flowers), etc...
 
Nizza

Nizza

Well-Known Member
hyroot said:
^^^^^^^ since writing that book and helping develop led's if you seen his speech about led's. He did a 180 on that said that leds' are missing green light until they have that they will suffer in yield....not exact words.... Alot of the older growers logic way back when do not hold up any more. They even thought soil is trash when a plant is done. That couldn't be further from the truth.
Click to expand...
I thought he was saying that it is important for photosynthesis there, but also saying that the green/blue light doesn't effect the photoperiod ("flowering") if it's strictly green/blue as in LED (he also says fluoro)?
I get what your saying though, i'm interested in that
where can i read more about his LED experience?
 
MrEDuck

MrEDuck

Well-Known Member
I think this is rather misleading. Plants do use green light in photosynthesis, but that has nothing to do with it being safe in the dark period. I have a friend who grew a crop with 24/0 blue light from an LED and 12/12 from a CMH and he had no problems. Only a small increase in yield compared to growing normally though. The hormone responsible for telling the plant if it is dark relies on red light to be activated. So while the blue and green light causes photosynthesis it doesn't disrupt phytochrome production and interrupt the flowering cycle.
I would be careful with green CFLs as they do produce some red light, just like a metal halide can look extremely blue but still has some reds in it's spectrum. To not interefere with flowering a light must produce no photons in the 630-660nm range. I can't remember the exact numbers for phytochrome but that should be quite close.
 
You must log in or register to reply here.
Top