Photosynthesis Under Solid State Light. Setting the Standards .

stardustsailor

Well-Known Member
Well...
Everybody's is allowed to make mistakes once in a while ...
:P
...

So,after having a small chat ,with a friend ,who BTW has a PhD in Molecular Plant Biology..:P..
And after I've presented to him ,the whole CS-RQE thing ....
He responded that while ,the thought is more than nice ,
actually is not an Relative Quantum Efficiency function.

It is just mj's photosynthetic apsorptance function ,quanta weighted ...

He did some explaining to detail about the action spectrums and the known standards ...
There's only one 'standard' accepted by the scientific community as "Quantum Efficiency " function.
And that is the McCree 1972,a one ...

So he showed me ,how to make a Cannabis Sativa L. dedicated Rel . Quantum Efficiency function plot ....

Anyway,not much time right now,to explain in detail ,how exactly is done .....

But here's the plot ...

CS_RQE_2014_b.JPG

( !! It can be used only with quanta flux - i.e. μmol/sec - units/ spectrum plots/ functions !! )

Cheers.
:peace:
 

Fiveleafsleft

Well-Known Member
So... If you guys had 27w of CXA 4000K on each of 8 small heat sink and could add four 3-watters on each.. How would you go around with this? Ideally 4 of them would be more inclined against seedling - early bloom and the other ones towards post-stretch - harvest. I have come up with a solution, but would gladly change that and compare the results! Maybe this is asking a lot? Anyways thanks for a very interesting thread!
 

Randomblame

Well-Known Member
So... If you guys had 27w of CXA 4000K on each of 8 small heat sink and could add four 3-watters on each.. How would you go around with this? Ideally 4 of them would be more inclined against seedling - early bloom and the other ones towards post-stretch - harvest. I have come up with a solution, but would gladly change that and compare the results! Maybe this is asking a lot? Anyways thanks for a very interesting thread!
Maybe some blue's, cyan and reds on a seperat driver and a autarc IR730 as Phytochrome-Trigger and as "late flower booster"?!
 

Randomblame

Well-Known Member
I hate to belabor the obvious, but does all of this mean we still have to build our own custom lights or is someone making a reasonable approximation of an LED grow light finally?
There are some chinese sellers with cobs with a special growing phosphor(looks more orange) but no Idea if it is not just only a thicker phodphorous layer of a 1.900k cob?
 

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Randomblame

Well-Known Member
Seems the Cree 4k/CRI70 have the most cyan and also the Vero Series gives the most cyan part in 4k spectrum!Cree have most cyan in 4k.pngMost cyan in 4k, but less as Cree.png
Also seems to have enough blue for open stomata and a good amount of red.
 
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coolbreez1

Well-Known Member
So what I get out of all of this is that my hunch on the 4000k lights was right on the mark woo hoo! It seems like as long as the intensity is high enough the 4000k should have more then enough blue to get the maximum reduction in internode spacing for veg, and the right distribution for flowering. Plus the over all synergistic effect of the 4000k should lead to pretty ideal trichome production. I am feeling pretty pleased right about now!
 

OneStonedPony

Well-Known Member
Interesting, but a bit technical. In laymen's terms, what's the best spectrum for veg, and for flower, and what lights do you think hit those best ? Thanks in advance.
 

AquariusPanta

Well-Known Member
Interesting, but a bit technical. In laymen's terms, what's the best spectrum for veg, and for flower, and what lights do you think hit those best ? Thanks in advance.
5000K is a popular choice for vegetating and 3000K for flowering. Cree CXA/B (2530, 3070, 3590) and Bridgelux Vero (10, 13, 18, 29) are the best of the best within the LED lighting realm.
 

OneStonedPony

Well-Known Member
Thanks for the info. I've stayed with a 400 watt MH (4200 spectrum), or a 360 watt engergy saver MH in veg for the longest time. I run a 400 HPS (2100) spectrum in flower. I want to buy a high end led setup, but seems like everytime I get some extra money, something ends up taking it: girlfriend, car repairs, rent increases, you know life. I would love the no heat issue for sure. Maybe I should work on some weekends, take that extra money just bite the bullet and do it. If there is a brand of led light you favor over others I'm listening. I get the Cree leds are good, but which lighting company has the best unit ?
 

Randomblame

Well-Known Member
Thanks for the info. I've stayed with a 400 watt MH (4200 spectrum), or a 360 watt engergy saver MH in veg for the longest time. I run a 400 HPS (2100) spectrum in flower. I want to buy a high end led setup, but seems like everytime I get some extra money, something ends up taking it: girlfriend, car repairs, rent increases, you know life. I would love the no heat issue for sure. Maybe I should work on some weekends, take that extra money just bite the bullet and do it. If there is a brand of led light you favor over others I'm listening. I get the Cree leds are good, but which lighting company has the best unit ?
Hey OSP!

If you want a grow light based on the latest efficient Cobs, look at this thread from JimmyIndika:

https://www.rollitup.org/t/vero18-and-vero29-test-grow.874814/unread

You can buy the Optics lights also with Cree Cobs, but look for the newer CXB versions because of the better efficiency. If you have enough time and not two left hands consider to build a DIY. It's very easy to make and there are many threads about how it goes. And at last, you can halve the cost or build it twice bigger.
 

salmonetin

Well-Known Member
...for my pov... offtopic posts...

There are some chinese sellers with cobs with a special growing phosphor(looks more orange) but no Idea if it is not just only a thicker phodphorous layer of a 1.900k cob?
....

Hey OSP!

If you want a grow light based on the latest efficient Cobs, look at this thread from JimmyIndika:

https://www.rollitup.org/t/vero18-and-vero29-test-grow.874814/unread

You can buy the Optics lights also with Cree Cobs, but look for the newer CXB versions because of the better efficiency. If you have enough time and not two left hands consider to build a DIY. It's very easy to make and there are many threads about how it goes. And at last, you can halve the cost or build it twice bigger.
...

....now on the final part of thread you recommend a comercial lamp... ...the end of the thread not so nice now...

...only my pov and modest opinion...

words from sds..

Well...
Everybody's is allowed to make mistakes once in a while ...
:P
...

....only once?... ...tropezamos... caemos... nos levantamos ...


saludos
 
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Randomblame

Well-Known Member
...for my pov... offtopic posts...

Hey Sal!
Sorry for the off topic posts. Maybe a bit too lazy! English is not my native language and Im unsing google translator, so please do not any word to weigh. Just wanted to answer the questions and will continue to say my mind in the future, if I have one.


....



...

....now on the final part of thread you recommend a comercial lamp... ...the end of the thread not so nice now...

...only my pov and modest opinion...

words from sds..

Well...
Everybody's is allowed to make mistakes once in a while ...
:P
...

....only once?... ...tropezamos... caemos... nos levantamos ...


saludos
 

bicit

Well-Known Member
So... If you guys had 27w of CXA 4000K on each of 8 small heat sink and could add four 3-watters on each.. How would you go around with this? Ideally 4 of them would be more inclined against seedling - early bloom and the other ones towards post-stretch - harvest. I have come up with a solution, but would gladly change that and compare the results! Maybe this is asking a lot? Anyways thanks for a very interesting thread!
If it were me, i would get some 3 chip led stars from Steve's led with a 620nm and two 660nm leds.

Others may have different ideas.
 
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