The dark period - how dark should it be

[Guest]

Hello fellow ICmagers :smile:

I find this theme interesting for a long time now, and I really dont know the answer for sure. What do you think about 100% darkness in our lights-off period?

Here are some questions to guide this theard;

Does it need 100% dark? Why? Why not?
What happends if you dont make it dark?
Why that happends?
What about outdoor strains?
Moon?
How much are genetincs involved in this (outdoor/indoor)?
Is there a problem if light gets in the box only one time?
Is there a problem if light is penetrating trough slots in growroom/box all the time?

And so on...

 

[Growdoc]

Hello fellow ICmagers :smile:

I find this theme interesting for a long time now, and I really dont know the answer for sure. What do you think about 100% darkness in our lights-off period?

Here are some questions to guide this theard;

Does it need 100% dark? Why? Why not?
What happends if you dont make it dark?
Why that happends?
What about outdoor strains?
Moon?
How much are genetincs involved in this (outdoor/indoor)?
Is there a problem if light gets in the box only one time?
Is there a problem if light is penetrating trough slots in growroom/box all the time?

And so on...

In my opinion Plants that are naturally from outdoors that are brought inside for breeding and commerical cultivation become weak geneticaly speaking, therfore causing them to behave in many different patterns. Some strains dont need it to be totally dark and some do, in my experience this does not make the strain bad or good.

my 2 cents...

Growdoc

 

[packn2puff]

I've wondered if it is also because you are force flowering and the plant using 24/0 or 18/6 then adjusted immediately to 12/12, where as nature shortens the light cycle over time. My timer even has this astrological mode. I wondered how slamming the light down to 12/12 affected the plant. Maybe light leaks cause the plant to be not completely convinced or confused(in a plant way, hormones, etc.) about the change in season.
Veg it doesn't really matter, many like using 24 hrs light. I think your only problem would be not being able to get your plants to flower easily till the plant is convinced the photoperiod has changed and any light will generate some photosynthesis and since it is receiving light it may not be "convinced" and able to change over. Like Growdoc said, I believe this has alot to do with genetics and some strains have spent their generations in different astro seasons and exposer in reference the equator. The plant doen't have eyes but it knows light is there via photosythesis. So it would seem that the photosensitivity of the plant or strain may be why some will and some won't flower if light leaks. These are only my opinions, many may have better answers, I haven't studied much out this yet. Hope to see you around Tic and Growdoc is Da Man.

 

[GMT]

It maybe diff for plants with sativa genetics, but with many indicas it certainly isnt something to worry about, assuming your lights are on in the day and off at night. Remember, even normal household lights arent any good for generating photosynthesis
so your plants will hardy notice them if shaded. Certainly a bit of household light through a crack wont keep them in veg.

 

[Guest]

I keep my lights out period as dark as possible out of habbit.
Ive heard some interesting conversations about the moon light in nature outdoors and i assume not all outdoor plants do actually get 100% dark period but what light the moon gives off i dare say is very different to the light in our rooms...

 

[Guest]

Hello Doc, p2p, GMT, Leeroy!
Thank you for stoping by this theard. It is interesting reading your posts.... Will write myself about it, just i have to take some time.

I got another question to add.

Moon reflects light from the sun. How this effects spectrum of light?

Take care, Tic

 

[Guest]

Thats right, i forgot about that, the moon does reflect the light of the sun...hmmm
thats interesting...and it totally debunks my last statement about moonlight being different to our grow room light

Oh i am happy to be wrong, its not the first time and it wont be the last lol


I guess the question would be then, what intensity is that light that is being reflected?

Could it have only a reflective property and not able to transmit the suns energy at that low level to effect the pklants at night maybe?

 

[Growdoc]

Moon light...

Moon light...

We all know that plants respond to light Spectrum, the sun that hits the moon and lights up the night sky has traveld way passed the earth hit the moon and refelcted back giving off a totally different spectrum then normal sunlight...

 

[Guest]

Thats what i was pondering...thanks for clearing that up

 

[Growdoc]

My pleasure mate...

 

[Guest]

Hey Doc

I can't believe total darkness is necessary for any growing thing. In fact, total darkness seems to be a very unnatural state, with it occuring (with a few exceptions) only in a cave and deep in the ocean. I don't see how blackness in an indoor grow room recreates any normal state a plant would have experienced in its entire genetic history.

An expereinced grower I once knew years ago did experiements in his 6000 watt flower room using a 400 MH and a light meter. According to him, his plants in flower could handle almost 8-10% of the flower light illumination in the dark period and still maintain it's photoperiod. While I have no ability to recreate this claim, I have seen little in my own room to make me believe it's not a correct observation.

 

[Guest]

We all know that plants respond to light Spectrum, the sun that hits the moon and lights up the night sky has traveld way passed the earth hit the moon and refelcted back giving off a totally different spectrum then normal sunlight...

Now my common sence tells me different. What we get is not totaly different specturm. What we get is whole spectrum, just that some wawlengs are less present than normal. The question is what lenghts are that and how less are they presented in moonlight. Dont forget, sun covers big piece of specturm. And wawelenghts doenst change while they travel. They can be stoped by "filters" tho.

 

[Ronley]

I grow on my balcony on the 9th floor above the city. In addition to the city lights I have the upstairs neighbours kitchen light splashing all over the balcony. Only when they do turn it off after midnight, then i get relative darkness, Well as much as a 9th floor balcony above a city can give...

While this is not ideal, my plants still grow very well and the buds are doing very nicely. BUT instead of the buds forming uniformally, the bottom branches devellop a lot faster then the upper branches. In fact the bottom branches are already into its 2nd week of flowering while the upper branches still have not started.

During the cold winter months I brought in the plants every night and then they had compleate darkness for about 6 plus hours, now that its warmed up and there is no fear of heavy winds and cold I leave them outside.

I will organises a balcony covering which will shield the whole balcony from my neighbours light. and then I will have better darkness.

I had only 1 "outbreak" of hermie flowers on one plant, But I immediately destroyed, the hermie flowers, and got about 10 seeds in total. I was lucky.

 

[Guest]

Would anyone comment my statements? :|

 

[GMT]

What ya worrying about now mate? Come on, you know your grow will be ok with a few leaks, and ya answered your own question on the other thing. But if ya really want a comment on it, remember the way the wavelengths are affected by the moon will depend upon whether the moon is getting closer or further away when you measure them.

 

[packn2puff]

More Light Reading

More Light Reading

Now my common sence tells me different. What we get is not totaly different specturm. What we get is whole spectrum, just that some wawlengs are less present than normal. The question is what lenghts are that and how less are they presented in moonlight. Dont forget, sun covers big piece of specturm. And wawelenghts doenst change while they travel. They can be stoped by "filters" tho.

You have to be very careful in distinguishing the spectral distribution of light from its "color". The spectral distribution is the intensity (number of photons / area) vs. wavelength (or frequency). "Color" refers to the response of the eye and brain to light. They are not the same thing. Visible light from the Sun is approximately "white" in the sense that the spectral intensity distribution of visible radiation is essentially constant (above the atmosphere). The apparent yellow "color" of sunlight arises from two origins: preferential scattering of blue light by the atmosphere and the higher sensitivity of the eye to yellow wavelengths compared to other wavelengths of the same spectral intensity. The "whiteness" of moonlight is due for the most part from the fact that it is faint. At low levels of intensity the eye loses its sensitivity to "color". You can demonstrate this be trying to distinguish different colors in a darkened room. It is difficult because the receptors in the eye that distinguish color are not sensitive to low intensities of light. Also recall if you have seen any "moon-rocks" that they are dark gray -- almost black -- so the moon is a very poor reflector of the incident light from the sun. And sometimes when the moon is low on the horizon it is brownish, which is a dimmer form of yellow. In short, the sun shines white into space, the moon is neutral gray so it reflects the same percentage in all colors, so it is a dimmer white, and then the atmosphere you see it through (whether moon or sun) may or may not take out some of the blue, making it yellowish.
This would be why Caprichoso is correct about intensity or amplitude is more of a factor, then spectrum, The whole sun's spectum is there, but does it get to the earths surface that way?
Solar radiation is partially depleted and attenuated as it traverses the atmospheric layers, preventing a substantial portion of it from reaching the earth's surface. This phenomenon is due to absorption, scattering, and reflection in the upper atmosphere (stratosphere), with its thin layer of ozone, and the lower atmosphere (troposphere), within which cloud formations occur and weather conditions manifest themselves.
The stratospheric ozone layer has a strong absorption affinity for solar UVR, depending on wavelength. The troposphere is an attenuating medium. The solar radiation is reflected and scattered primarily by clouds (moisture and ice particles), particulate matter (dust, smoke, haze, and smog), and various gases. The two major processes involved in tropospheric scattering are determined by the size of the molecules and particles and are known as selective scattering and nonselective scattering.
Depends on what's in the atmospheric soup and the phase angle which means the spectral distribution is very relative to many variables.
Now my head hurts..time to smoke a fan leaf. That's all I feel like commenting right now Tic.

.......................................Light Chart.....................................................................................Lunar Spectrum....

 

[GMT]

lol packn

 

[Growdoc]

That is some good info mate...

Speed of light is not constant, its made up of short and long wave lengths...

 

[GMT]

Ah, now, the speed of light Is constant, just the frequency can shift. Like getting hit in the head by one basket ball traveling at 10mph every 10 seconds or 5 seconds, the speed of the balls is constant, just the frequency changes. The intensity of the light is like one ball or 10 hitting you every 10 or 5 seconds, but still at the constant 10mph. (substitute basket balls for light photons and you're there) :smile:
:friends: Sorry Doc, just couldn't stand by while Einstein got libled

 

[Guest]

Waaa, I will have to wait for tomorrow to read this. I'm too high now to understand anything.

Thanks