Experienced LED Pro's Help with Red Spectrum Ratios

The ratio between 630nm and 660nm....

First I would look at the specs of each of those LEDs, what is their entire range and what is their output at the recommended voltage and current?

For example, different 660nm's will have different ranges and outputs, some may be 655-660nm, 660-665nm, 650-660nm, 655-665nm, 640-660nm, 655-670nm, etc.... But they are all advertised as "660nm". Those narrower ones if used in excess, can and probably will cause stunted growth and bleaching. 630nm, and every other color are like that too, and for the most part, all blue LEDs are very narrow and only cover 2-5nm per each, so if too much blue is used, not only will you stunt your plants, they will probably bleach too. A lot of people are not aware of the differences between one LED to the next, and try too hard to get enough targeted light to the bottoms of 3-4 foot tall plants by using extra 660nm, and narrower lenses, while they are getting better 660nm coverage at the bottoms of the plants, they are hurting the tops of their plants.

In my experience, it is best to try to spread the color out as much as possible, and cover as much colors as you can without adding too much of any 1 concentrated color. On the red side, you'll want to cover as much from 600-670nm as you can, favoring the 670nm side a little heavier, then also 5-10% of the total LEDs should go to farred 720-750nm.

The most important spectrum that is left out in a lot of LED grow lights, is the 500-600nm area. 65% of the color I use is from 620-670nm and 720-740nm, 10% to 400-500nm, and 25% to 500-620nm.

White LEDs are a great thing, you could easily omit all the blues and greens if you use them, and swap them for a cool white LED.

Here is a typical color spread of a cool white LED:

410-420nm: 1.4%
420-460nm: 23.75%
460-490nm: 4.5%
490-525nm: 11%
525-565nm: 22.7%
565-600nm: 16.35%
600-620nm: 6.35%
620-640nm: 4.5%
640-655nm: 3.35%
655-675nm: 2.3%
675-700nm: 2.0%
700-750nm: 1.8%

To achieve 10% blue in your overall LED mix, simply use 1:2 ratio, 1 cool white per 2 red/farred.

Good luck with your next LED light

Originally Posted by Eraserhead

Those narrower ones if used in excess, can and probably will cause stunted growth and bleaching.
630nm, and every other color are like that too,
and for the most part, all blue LEDs are very narrow and only cover 2-5nm per each,
so if too much blue is used, not only will you stunt your plants, they will probably bleach too.

Great information, but the LEDs are not that narrow, or am I reading you wrong.
Looking at the chart I would say 75% of the light is 50nm wide

Luxeon Star Royal Blue

Source click image:


Now lasers on the other hand they are narrow.
I wonder how a seedling would act if illuminated by a red laser though a widening lens.


Source click image:


Green4me2 - "I have built a couple panels and have had moderate success"
Can we seen them, or are they secret

The LEDs will vary from name brand to name brand. Look at the specs of a Bridgelux Blue.

447.5 to 450nm BXCE4545447- F1-z BXCE4545447- F2-z BXCE4545447- G1-z
450 to 452.5nm BXCE4545450- F1-z BXCE4545450- F2-z BXCE4545450- G1-z
452.5 to 455nm BXCE4545452- F1-z BXCE4545452- F2-z BXCE4545452- G1-z

455 to 457.5nm BXCE4545455- F1-z BXCE4545455- F2-z BXCE4545455- G1-z

457.5 to 460nm BXCE4545457- F1-z BXCE4545457- F2-z BXCE4545457- G1-z
460 to 462.5nm BXCE4545460- F1-z BXCE4545460- F2-z BXCE4545460- G1-z
462.5 to 465nm BXCE4545462- F1-z BXCE4545462- F2-z BXCE4545462- G1-z

The reason some LEDs will show a wider spectrum, is because the graphs do not show the breakdown between different bins. The graphs with these Bridgelux will show 447.5nm-465nm, but it will take 7 different LEDs to achieve that.

A Cree XPE royal blue covers 450-465nm, and you will only need that 1 diode to achieve it.

Originally Posted by Rasser

Great information, but the LEDs are not that narrow, or am I reading you wrong.
Looking at the chart I would say 75% of the light is 50nm wide

Luxeon Star Royal Blue

Source click image:


Now lasers on the other hand they are narrow.
I wonder how a seedling would act if illuminated by a red laser though a widening lens.


Source click image:


Green4me2 - "I have built a couple panels and have had moderate success"
Can we seen them, or are they secret

And I'm still not convinced if all this wide spectrum focus is hype or science

For I keep coming back to this "Illumitex Horticulture LEDs in World's largest Indoor Vertical Farm"

From Lumitex website.



And it looks like you can buy the LED's from here: http://www.mouser.com/illumitexhorticulture/
But all the data sheets that could revile the spectrum used, are removed, and I can't find'em on Lumitex's site either.

But there is still something on the net that show the spectrum.


Link to giant image of spectrum's used in the "Available Spectra" image above. A must see !
http://blog.globalhardwarestore.com/...Chart-JPEG.jpg

So the questing is, if people make such a big investment in the worlds largest grow room
and use what looks to be F1 or F2 spectra with only red and blue LEDs, then why should
we use anything else ?

The LED Tomato Test
Ranking:
1) uv + red + blue
2) red + blue
3) red + blue + green
3) red + blue + yellow
4) red + blue + orange

I think that tomato test could have been done better. They limited their testing to just a couple color mixes, and no where is there any white. If they used white + red + farred, it would have trumped all the other results, even blue + white + red + farred would have done better for them.

All my info on spectrum is based on looking at spec sheets from manufacturers, and also personal experiments. I've been studying and researching LEDs for a few years now, and just recently started selling them. Besides the white LEDs I use, the reds have a 10nm width each, and 5nm with the blues.



Like every LED on the market, one will vary from one to the next, I've looked at the Illumitex LEDs, they are for sale in a few places, I never looked at their specs because the cost is not practical yet and they do not interest me at this moment, but maybe theirs is made up differently, they definitely use different kinds of LEDs, there is multiple smaller chips making up the entire bulb, there could very well be more than 1 bin in there to complete a fuller spectrum, almost positive that is the case.

The LED Tomato Test
Ranking:
1) uv + red + blue
2) red + blue
3) red + blue + green
3) red + blue + yellow
4) red + blue + orange

Wow great info everyone! I am not exactly convinced just yet on the full range leds yet either, but i see and understand both sides of the argument and I cant decide if one is truly superior to the other.

My last panel did just as Eraserhead described. It stunted growth and i believe it may have been due to an overload in blue and violet leds.

Eraserhead in your experience what do you prefer for a ratio of 630nm to 660nm leds? Given the thought that both the 630nm and 660nm leds emit equal amounts of radiant energy. 2 660nm leds to 1 630nm led? Or do you consider that to be to much 660nm?

I would try to get at least one more red color in between the 630nm and 660nm, such as 640nm. I'd do the ratio as follows: 630:640:660 2:2:3, if you went with just 630nm and 660nm, I'd do 630:660 2:3

If you add cool white into the mix, I'd do cool white:630:640:660 3:2:2:3, or cool white:630:660 2:2:3

Originally Posted by green4me2

Wow great info everyone! I am not exactly convinced just yet on the full range leds yet either, but i see and understand both sides of the argument and I cant decide if one i truly superior to the other.

My last panel did just as Eraserhead described. It stunted growth and i believe it may have been due to an overload in blue and violet leds.

Eraserhead in your experience what do you prefer for a ratio of 630nm to 660nm leds? Given the thought that both the 630nm and 660nm leds emit equal amounts of radiant energy. 2 660nm leds to 1 630nm led? Or do you consider that to be to much 660nm?

Originally Posted by Eraserhead

I would try to get at least one more red color in between the 630nm and 660nm, such as 640nm. I'd do the ratio as follows: 630:640:660 2:2:3, if you went with just 630nm and 660nm, I'd do 630:660 2:3

If you add cool white into the mix, I'd do cool white:630:640:660 3:2:2:3, or cool white:630:660 2:2:3

Thanks! I really appreciate the advice, now its time to save up and build another panel.