LED Efficiency: Red/Blue vs White

[Bubbleblower]

Photosynthesis actually only catches from about 0.1% to 2.0% at best. Its incredibly inefficient. If it could capture 95% of light, the plants would look very dark! Most of the sun's light either bounces back into space or becomes heat.

It doesn't absorb 95% of the light, but uses 95% of the light, may be I could have worded that better. What you mean is this:

"Photosynthesis is the most important biological process on Earth. It serves as the World's largest solar battery. The primary reactions have close to 100% quantum efficiency (i.e., one quantum of light leads toone electron transfer); and under most ideal conditions, the overall energy efficiency can reach 35%. Due to losses at all steps in biochemistry, one has been able to get only about 1 to 2% energy efficiency in most crop plants. Sugarcane is an exception as it can have almost 8% efficiency. However, many plants in Nature often have only 0.1 % energy efficiency"

You need standards to determine that, but if there are action spectra we don't know about these standards are wrong.
For example the heat you talk about is very important for flowering, it's not 100% wasted.

 

[cocogrower]

I was about to try it with HPS from the start, and maybe turning on side lights maybe not. Then I had some friends get very dramatic about something and was too worried they were going to turn me in for something else(rescuing cats without a license...) so I scrapped the grow setup for a while. I've got 3 plants that are about 16-18 inches tall right now though and I am going to stick them in the flowering chamber as soon as I can get that room ready again....

This is so Funny! I always knew canna growers were the real sweet-harts! LOL

 

[magiccannabus]

haha yeah I'm always representin the kitties yo

 

[cocogrower]

haha yeah I'm always representin the kitties yo

LOL:kitty:

 

[HydroGrowLeds]

http://onlinelibrary.wiley.com/doi/10.1002/elsc.201400057/abstract

A fun read on why it is important to balance specific wavelengths and pair them together for optimal growth rates/yields:

Far-red (FR) light is crucial for the efficiency of photosynthesis and photomorphogenetic activity. This study investigated whether FR light at different wavelengths affects the Chlorella vulgaris biomass growth rate and chemical composition. For this purpose, FR was added to the blue–red (R) light at the wavelength of 720 nm (BRFR720L [blue + R + FR 720 nm light]) or 740 nm (BRFR740L [blue + R + FR 740 nm light]). BRFR740L allowed both higher growth rate and increased amount of total biomass compared to BRFR720L (blue + R + FR 720 nm light). The chemical composition of C. vulgaris biomass, analyzed by FT-Raman spectroscopy on lyophilized cells, significantly correlated with the applied FR component. The differences in lipid, carotenoid, and chlorophyll contents were particularly evident and all were higher in BRFR740L. Fluorescence emissions spectra of C. vulgaris cells were measured in the range 420–800 nm in the cuvette equipped with a magnetic stirrer preventing sedimentation of the cells during measurement. In the blue–green range (420–650 nm) fluorescence emission spectra indicated that changes in the chemical composition of phenolic compounds in the algae depended on the wavelength of FR used in LED matrices. This work showed that the use of FR of a wavelength 740 nm in the bioreactor's light source significantly improves biomass production of C. vulgaris cultures.

Hydro Grow has been using 740nm since our second prototype in 2008.

 

[PetFlora]

http://onlinelibrary.wiley.com/doi/10.1002/elsc.201400057/abstract

A fun read on why it is important to balance specific wavelengths and pair them together for optimal growth rates/yields:

Far-red (FR) light is crucial for the efficiency of photosynthesis and photomorphogenetic activity. This study investigated whether FR light at different wavelengths affects the Chlorella vulgaris biomass growth rate and chemical composition. For this purpose, FR was added to the blue–red (R) light at the wavelength of 720 nm (BRFR720L [blue + R + FR 720 nm light]) or 740 nm (BRFR740L [blue + R + FR 740 nm light]). BRFR740L allowed both higher growth rate and increased amount of total biomass compared to BRFR720L (blue + R + FR 720 nm light). The chemical composition of C. vulgaris biomass, analyzed by FT-Raman spectroscopy on lyophilized cells, significantly correlated with the applied FR component. The differences in lipid, carotenoid, and chlorophyll contents were particularly evident and all were higher in BRFR740L. Fluorescence emissions spectra of C. vulgaris cells were measured in the range 420–800 nm in the cuvette equipped with a magnetic stirrer preventing sedimentation of the cells during measurement. In the blue–green range (420–650 nm) fluorescence emission spectra indicated that changes in the chemical composition of phenolic compounds in the algae depended on the wavelength of FR used in LED matrices. This work showed that the use of FR of a wavelength 740 nm in the bioreactor's light source significantly improves biomass production of C. vulgaris cultures.

Hydro Grow has been using 740nm since our second prototype in 2008.

Do you agree that incorporating some crap FR diode that doesn't last very long just so it can be said panel XYZ has them would be just more BS sales hype?

Yes? Then please tell us whose FR diodes you've been using, and how hard you drive them you know, since 2008

 

[HydroGrowLeds]

Hi Pet

Not sure what all the hostility is about, but there are many respected manufacturers of 740nm LEDs including LED Engin: http://www.ledengin.com/files/products/LZ1/LZ1-00R300.pdf

In fact when you read their PDF where it says "Typical Applications" it states "Horticulture".

When you call LED Engin and ask "Hey does your 740nm have a lower lifespan than your 660nm?" Their response is "No". But we talk with reps from these companies on a daily basis and thus this information is second nature to us. You can look at the spec sheet for their 740nm - nowhere does it state the life is any less than any of their other LEDs. I'm not sure where you're getting your information from, but posting misleading information (like 740nm's don't last long) without anything to back it up is the definition of begin belligerent - you're just looking to fight. We're not on this forum to fight, nor is this forum here for people to fight on. We're here to have a respectable debate since our science-based opinions differ with yours.

And not to rain on your parade (because I know you like white LED grow lights) but any of the white lights you're buying from any company are going to give a max of about 120 lumens per watt. HID is still more efficient at producing white light - so even if you have 1000W of white LEDs it's not as powerful as a 1000W HPS.

Yes, there are "super chips" out there where Cree brings them into negative temperatures to see how much efficiency they can squeeze out of a chip, but this is not practical application. Just look at Home Depot or Lowes - the white LED lights you see in the stores are 70-90 lumens per watt. Your LED grow lights are going to be marginally better, but still not as good as HID at producing visible light for humans.

And for what it's worth - our LEDs are driven at 550mA.

 

[cocogrower]

http://onlinelibrary.wiley.com/doi/10.1002/elsc.201400057/abstract

A fun read on why it is important to balance specific wavelengths and pair them together for optimal growth rates/yields:

Far-red (FR) light is crucial for the efficiency of photosynthesis and photomorphogenetic activity. This study investigated whether FR light at different wavelengths affects the Chlorella vulgaris biomass growth rate and chemical composition. For this purpose, FR was added to the blue–red (R) light at the wavelength of 720 nm (BRFR720L [blue + R + FR 720 nm light]) or 740 nm (BRFR740L [blue + R + FR 740 nm light]). BRFR740L allowed both higher growth rate and increased amount of total biomass compared to BRFR720L (blue + R + FR 720 nm light). The chemical composition of C. vulgaris biomass, analyzed by FT-Raman spectroscopy on lyophilized cells, significantly correlated with the applied FR component. The differences in lipid, carotenoid, and chlorophyll contents were particularly evident and all were higher in BRFR740L. Fluorescence emissions spectra of C. vulgaris cells were measured in the range 420–800 nm in the cuvette equipped with a magnetic stirrer preventing sedimentation of the cells during measurement. In the blue–green range (420–650 nm) fluorescence emission spectra indicated that changes in the chemical composition of phenolic compounds in the algae depended on the wavelength of FR used in LED matrices. This work showed that the use of FR of a wavelength 740 nm in the bioreactor's light source significantly improves biomass production of C. vulgaris cultures.

Hydro Grow has been using 740nm since our second prototype in 2008.

How many % without causing stretch is the question I've found it difficult to find an answer for.. Stretch in chlorella maybe is less of a problem..

 

[cocogrower]

I do think that you make some valid points. The best probably is to mix those "super-chips" with a certain amount of 630-660.. I just swapped 260w of "cidly - Blue/white/red-light" against 120w "cree - 150 l/w Superchip combined with most efficient 630-660nm. Now I only have three plants in late bloom, but so far, (24h) they seem very happy about the change) In my next round i will use about 200w of superlight and hope to outperform the old cidlys with good margin. HID-lights are about as effective as the best cobs right now - lumenwise that is. But HPS still put out almost all the light in the orange spectra, that we see very well, hence the good lumen.. Anyways I have to say that my plants were happier under HPS than under my cidly-lights... This actually make me wonder.. if plants are that picky? Orange light isn't known to drive photosynthesis very well, yet they thrive under HPS.. Sorry for the rambling, and maybe bad english to, it's really getting late here..

 

[cocogrower]

Do you agree that incorporating some crap FR diode that doesn't last very long just so it can be said panel XYZ has them would be just more BS sales hype?

Yes? Then please tell us whose FR diodes you've been using, and how hard you drive them you know, since 2008

This is a fair question to ask any vendor of any grow-light - about all their leds.. In case you're not satisfied with "the best on the market" "outperforming HID" "top bins used".

 

[Bubbleblower]

When you call LED Engin and ask "Hey does your 740nm have a lower lifespan than your 660nm?" Their response is "No". But we talk with reps from these companies on a daily basis and thus this information is second nature to us. You can look at the spec sheet for their 740nm - nowhere does it state the life is any less than any of their other LEDs. I'm not sure where you're getting your information from, but posting misleading information (like 740nm's don't last long) without anything to back it up is the definition of begin belligerent - you're just looking to fight. We're not on this forum to fight, nor is this forum here for people to fight on. We're here to have a respectable debate since our science-based opinions differ with yours.

What science is that?
740nm gets warmer so has a lower lifespan than 660nm.

Orange light isn't known to drive photosynthesis very well, yet they thrive under HPS...

The more light the better it gets. Red and Blue are only as efficient as advertised at low light intensities using "less efficient" colors besides.
This is why we need orange, just like any other color;

"the carotenoid β-carotene plays a vital role in the photosynthetic reaction centre where, due to quantum mechanical reasons arising from the symmetry of the molecule, it provides a mechanism for photoprotection against auto-oxidation. They also participate in the energy-transfer process"

"Chlorophyll a absorbs indigo and red lights, b absorbs blue and orange -red, c absorbs blue and orange in smaller amounts"


Led's do have great potential and it is too bad we get so much wrong information from sellers in it for a quick buck.