Which wavelengths to choose
- Thread starter boneclone
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churchhaze
Well-Known Member
I can honestly say I've never tried using any red leds before (except for 730nm). I've only made white arrays so far. In practice, I'm not really sure what would be the best veg spectrum in terms of plant/leaf shape and makeup.Here,I've to disagree with you brother.
660 nm ,ain't the ideal reds for vegetative stage.
The 600-640 nm are far better ones,as they do not induce several things.
(thin stems - thick/waxy narrow bladed leaves,etc )
Cheers.
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stardustsailor
Well-Known Member
Nobody is 100% sure ,actually.
Those who claim otherwise ,they just lie or BSing ...
Keep in mind that even individual plants of same strain ,
will / can express different phenotypes under the same
enviromental conditions ,including light .
One thing is for sure.
White light seems to work ,more than fine actually ,both during vegetative and reproductive stage.
All the rest (mixing monos with whites or just mixing monos) up till now ,
are just pure assumptions or simply experiments.
( I can't find a certain paper ,that backs this up ,all the way ,about LEDS .)
Until we gather more -scientific or experimental- data and information for/about our beloved species ,white PAR spectrum light ,remains the only true viable solution.
Cheers.
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churchhaze
Well-Known Member
Speaking of color correction, when the only source of light in the room is 730nm, the leaves will start looking white because of the low absorbance of 730nm. It's very strange to look at. You wouldn't expect something green to reflect "red" so well.
It's very hard to show with a camera.
It's very hard to show with a camera.
Doer
Well-Known Member
I got it. 12% transmittance. Most is absorbed. More than the quantity transmitted, 12%, is reflected, however, 15%.Look,Doer...
~15 % of the green photons are reflected at the adaxial (upper) side of a leaf .
Thus the rest ~85 % is being absorbeb by the leaf.
From that 85% of photons ,~ 73% (of initial 100% ) is being absorbed by the PS systems ,
while ~ 12 % (of initial 100% ) is being transmitted from the abaxial side of the leaf ,towards deeper /lower leaves.
(Regarding Cannabis Sativa L. a "die-hard" , wild weed .)
That ~12% transmittance is forming the so called "green -window" .
Cheers.
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stardustsailor
Well-Known Member
It's not that much actually.
FR ( > 700 nm ) light is reflected more than 50% .
Actual plant /leaf tissue color ,simply remains " unknown " to us humans .
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Doer
Well-Known Member
So i am right, not wrong. Oh Man! That is what I said. You need green. Just Blue and Red are not enough.No,you 're wrong.
There are plenty more of issues ,regarding monochromatic LED emitters.
Green wls or photons MUST be there ,at least at higher PAR levels.
And better not to be in the form of individual green monochromatic leds,because several issues might arise.
(Local Shade avoidance syndrome is amongst of them .And plenty more.)
PAR spectrum is officially rendered as the wl region of 380-780 nm .
Not 380-500 nm and 600-780 nm .
Reference spectrum for plant biology study and research is always "WHITE LIGHT" ...
Not BLUE & RED ,alone.
GREEN light is always there ,too.
HIgher ,light -needy plants ,CAN NOT reach their MAXIMUM GENETIC POTENTIONAL ,without it .
RED & BLUE LED combos ,work well only in certain plant species and/or with certain cultivating techniques and/or LOW PAR levels.
Cannabis Sativa L. species ,will never reach their max genetic potentional without green photons.
And that is a well proven fact .NOT just a theory.
Cheers.
So, wrong. I was right.
Doer
Well-Known Member
Not even 12%. Even more to my discussion point.
bicit
Well-Known Member
So if one were seeking to enhance quality (terpene production), UV, and 600-640nm light would be good places to start? Am I understanding correctly?Here,I've to disagree with you brother.
660 nm ,ain't the ideal reds for vegetative stage.
The 600-640 nm are far better ones,as they do not induce several things.
(thin stems - thick/waxy narrow bladed leaves,etc )
Cheers.
Doer
Well-Known Member
UVB specifically. 290-320
stardustsailor
Well-Known Member
Oh ...Doer ...And something else ...
-The idea that matter is made up of discrete units is a very old one, appearing in many ancient cultures such as Greece and India. The word "atom", in fact, was coined by ancient Greek philosophers.
-" And yet it moves" ..Galileo Galilei ,1616 AD...
And many more ...
Date ,is not a reasonal basis for placing doubts ...
Nothing has changed from 1972.
All the recent findings ,support what McCree had discovered back then.
Cheers.
- The concept of a spherical Earth dates back to ancient Greek philosophy from around the 6th century BC.
-The idea that matter is made up of discrete units is a very old one, appearing in many ancient cultures such as Greece and India. The word "atom", in fact, was coined by ancient Greek philosophers.
-" And yet it moves" ..Galileo Galilei ,1616 AD...
And many more ...
Date ,is not a reasonal basis for placing doubts ...
Nothing has changed from 1972.
All the recent findings ,support what McCree had discovered back then.
Cheers.
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AquariusPanta
Well-Known Member
I'm under the presumption that UVB enhances resin. I don't know enough about terpene production to understand whether or not that is included with resin but I do know more resin/ice is desirable.
churchhaze
Well-Known Member
I would add 400-430nm if i was looking to broaden the spectrum for quality, but like SDS said, this is just bullshit speculation. I've never actually done it. I would assume that range would excite the cryptochrome system, and is not provided by the white cobs already.
stardustsailor
Well-Known Member
OH ! Ok ,my mistake ,please excuse me ,english is not my native language.
I 've misunderstood you !
Cheers.
AquariusPanta
Well-Known Member
Beautifully worded, Sailor. It may have been Heraclitus that left a fragment on the concept of atoms. I know that Epicurus touched upon it in his discourses.Oh ...Doer ...And something else ...
- The concept of a spherical Earth dates back to ancient Greek philosophy from around the 6th century BC.
-The idea that matter is made up of discrete units is a very old one, appearing in many ancient cultures such as Greece and India. The word "atom", in fact, was coined by ancient Greek philosophers.
-" And yet it moves" ..Galileo Galilei 1616...
And many more ...
Date ,is not a reasonal basis for placing doubts ...
Nothing has changed from 1972.
All the recent findings ,support what McCree had discovered back then.
Cheers.
Greek philosophers are, so far, my favorite to read about. I haven't found a better writer/thinker than Plato.
stardustsailor
Well-Known Member
Very complicated issue.
You can't have all.
(I guess so ...
)Nobody is actually aware of the limits & thresholds of actual rad Watts (or umol/sec)
needed to enhance either the quality or quantity..
A tad less and won't work as expected ..
A tad more and catastrophe sets in ...
And always in relation with the rest of light wls ...
Complicated enough ...
A simpler way would be to "imitate " sunlight ...
But still ,that is complicated enough by it's own ,as sunlight is not "constant" ,
at any of it's variables/ characteristics .
(Quantity,quality ,period,angle & diffusion )
Cheers.
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Doer
Well-Known Member
Could have fooled me, brother... Wait. You did.OH ! Ok ,my mistake ,please excuse me ,english is not my native language.
I 've misunderstood you !
Cheers.
rob333
Well-Known Member
this one right here
stardustsailor
Well-Known Member
stardustsailor
Well-Known Member
No,really.Could have fooled me, brother... Wait. You did.
English is not my native language.
Nor I've been to any kind of school to learn English.
Just traveled enough .
Cheers.