Excellent job! Thank you for sharing your thoughts. SmartBee has very innovative stuff, although I’m more familiar with Growtronix
How do you like working with the SmartBee equipment?
Are you noticing a significant savings in your electric bill since you changed from HID? Is heat easier to manage? Are the Spectrum King LEDs eligible for rebates from your electric company?
Here are a few more Spectral charts you may find helpful. Since your fixtures are white light, it may be worth looking into the Photosynthetic purple bacteria that will help optimize light absorption. Hope this stuff helps.
My thoughts on green light revolve around the fact that plants for eons have evolved in the sun’s light, which includes the green portion. While the majority of their pigments don’t absorb in the green spectrum, a few reach into it, particularly the carotenes and xanthophylls.
I don’t think it hurts to have a green spectrum. Is it worth the cost though? I couldn’t say.
Pure white lights bleed into yellow and green as a result of the phosphor coating over the LEDs. So I wouldn’t say it is intentional in most cases. One could argue that you are wasting energy with that kind of spectrum much like many LED manufacturers claim HPS lights waste energy on the large amounts of orange and yellow they produce.
Blue and red LEDs are the most cost effective to produce. White LEDs are actually just phosphor coated blue LEDs, so naturally they are slightly more expensive than blue LEDs.
As far as the importance of the 500-560nm spectrum. It isn’t necessary. It’s been proven that you can get great growth rate and results with only 440-450 paired with ~660. This is most relevant with high turnover low dollar crops like leafy greens, and micro greens.
With light intensive crops like Cannabis, I believe there is a benefit to include the 500-560nm spectrum. Though the benefits are still unclear, and debated. Some say it helps increase the penetration of the other spectra.
SmartBee Controllers has been a blessing in a lot of ways for me. From being able to detect when the plants aren’t uptaking by looking at dehumidifier data to tracking drinking patterns - for me the Irrigation tools are the best and have my back. For example last night the plants medium dried to below my set point and the system irrigated all while I was asleep in my bed. Here’s a recent pic of the garden data
Thank you for your thought Hunter!
Thanks for sharing your thoughts!
@cirrusledgrowlights Will you please post a image of your spectrum? If at all possible we would like to see the red 660nm strength of your LED two feet directly under the light. Thanks!
@nicholas Hey great find on the Plos article for photosynthesizing bacteria. Here is another piece of their work which was a foundation principle for the LED research. Its from 2014 though and with a sector as competitive and innovative as LED lighting… this stuff changes quick. Hope this helps!
Excellent, thank you very much. Now there are a few examples here.
Glad to see IR & UV included in your spectrum.
Yes we would like to see the numerical measurements of the 660nm wavelength specifically, two feet underneath the center of your fixture if possible? Can you specify what fixture this is, and the watt draw?
Here are the measurements from the Solar System 550 by California Light Works.
Parameter Value
PPFD (400~700 nm) 672.14 μmol/㎡s
PPFD IR (701~780 nm) 17.934 μmol/㎡s
PPFD R (600~700 nm) 483.24 μmol/㎡s
PPFD G (500~599 nm) 46.632 μmol/㎡s
PPFD B (400~499 nm) 142.34 μmol/㎡s
PPFD UV (380~399 nm) 0.5808 μmol/㎡s
YPFD (400~700 nm) 387.80 μmol/㎡s
YPFD (380~780 nm) 388.04 μmol/㎡s
YPFD IR (701~780 nm) 0.0000 μmol/㎡s
YPFD R (600~700 nm) 261.59 μmol/㎡s
YPFD G (500~599 nm) 13.965 μmol/㎡s
YPFD B (400~499 nm) 112.21 μmol/㎡s
YPFD UV (380~399 nm) 0.2362 μmol/㎡s
R/ B 3.39
R/ FR 26.95
DLI 58.073 mol/㎡
Illuminance
15573 lux
λp (380~780 nm) 647 nm
λD (380~780 nm) 0 nm
CCT 1792 K
CRI -5
The picture above is the spectrum for the Titan 3 and TItan 5. Not sure which this image was generated from, but the spectrum is identical.
when looking at UV, not all UV is the same and a Light Passport is not able to measure UV to its full range.
At Gavita we use a Maya UVA and UVB calibrated spectrometer to measure UVA and UVB output.
380 nm is interesting for aquatics and corals, not so much for plants.
Standard lamps, including the CDM, emit extremely low quantities of UV - see the Philips specifications of the lamp - as they are designed for use in every day life, not specifically for growing. UV ages materials, so the amount of UV is kept to a minimum by doting the glass and filtering it out. HPS also has UV blocking glass. The UV index of a CDM is 0.1
If you want “real” - UVA and UVB - you need a lamp which is designed for it.
Thanks for your UV thoughts @Theo Will you be able to share a spectrum chart of a 1000w Gavita? Do you think you can show us the measurements and values for the specific of UVA and UVB for your fixtures? Are there any UV studies you can reference for the group here?
If you have a moment, would also very much like to hear your thoughts on Far red 700-800nm specifically, and whether you think it should be incorporated into a grow light spectrum?
Appreciate your insight.
Here is the UV graph for the HPS lamps:
The plasma lights though have a UV transmitting filter for UVA and UVB in about the same ratios as the sun has. The intensity though depends on the PPFD of course, as it is a ratio.
There are countless studies about UVA and UVB, google is your friend. Here is one.
About far red: countless papers about that too and yes, far red should be part of the spectrum. Read about the Emmerson effect for example.
The_effect_of_ultraviolet_radiation_on_the_accumulation_of_medicinal.pdf (779.0 KB)
Is the joke that the graph is just a flat line, or was there an image to go there? 
@Theo Will you please post the spectrum charts again with the UVB and UVC data?
Its not coming through on this end. Thanks!
@Theo Will you also please share your opinion on White light LEDs compared to Pink light LEDs. Which is more expensive to manufacture? Why might a LED company choose to distribute White light LEDs over Pink? From your trials, which would you choose to use white or pink?
What can you tell us about the Gatvia LEDs? are they Pink or White? Can you share a spectrum chart and measurements from your LED fixture?
it’s no joke. It’s a flat line Hardly any worth mentioning.
there are no pink LEDS. Just red and blue which look like pink together. Come on guys!
They all have their application. White LEDs are basically phosphor covered blue LEDs so you have losses compared to the blue LED but still a better efficiency than discrete colors inbetween red and blue.
Use red and blue in for example a greenhouse as supplemental, white ones for a more wide spectrum indoor, combined possibly with red, far red and blue.
There is white and there is white. You won’t see the difference, a plant will. Your lcd screen shows only red, green and blue yet you perceive it as white together. A plant doesn’t: it sees three distinct peeks. Same with phosphor spectra.
