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The need for wavelength (nm) 380-480 in Medicinal plants

Here is a comparison of the Florida sun in October at 3:00PM, compared to a DE Genesis HPS bulb. The Lighting Passport spectrometer was four feet from the DE HPS bulb which was on for 20 minutes before the measurement. The comparison is bench marked to the Medical Plant curve which is the white line.

What are the medicinal benefits of adding or increasing the UV end of the spectrum the last two weeks of flowering?

How beneficial is it to have consistent blue light available to your plants for their entire life cycle?

How can we find the most economical way to provide this extra light to our projects?


Interesting info, thanks for sharing that. Is the yellow line the sun and the blue line the DE Genesis HPS bulb, or vice versa?

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Yeah, I wanted to ask. Chart needs a legend.

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Yes sir, the blue line is the DE HPS bulb, and the yellow line is the sun.


Check out the Ceramic Fixtures from Sustainable Growth Technology. They use a ceramic bulb that was originally developed to mimic sunlight. Their website is We have switched to these fixtures and they are crushing it.


So I see that:

Blue Line = Genesis DE HPS

Yellow Line = Sun

White Line = ?

HPS lights in general are not very effective at emitting UV lights by design. Nick brings up Ceramic Metal Halide lamps, Philips in particular that are putting out quite a bit of UV light. We’ve outfitted a lot of larger gardens with CMH lamps interspersed between their DE or SE HPS 1000w lamps. Almost every client has noted that their oil production has increased along with the testing of their THC cannabinoid levels increasing after implementing CMH. I’d highly recommend using them. Here’s a little diagram we made at that shows relative UV levels of the different CMH lamps on the market:


Hey Nick, very good suggestion. Will certainly take a look into these fixtures. Thanks for the thought.

Hey Nate, this is super helpful. Very good reference. So when using the lighting passport spectrometer the measurements can be referenced to a specific curve, like the Mcree curve for photosynthesis except this one is for Medical plants specifically.

The white line=Med curve

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Thanks for sharing the lighting passport! They also have great information on their website. Thats such a cool tool! This spectral graph was interesting to see. I use Spectrum King LED SK600 and loving the results. I wondered what your graph would like like if I super imposed the Spectrum King LED SK600 spectrum over the top and this is what I got. Anyway just wanted to add to the conversation :grin: Happy Growing


How are your results relative to HID lighting ? Is spectrum king the only LED you have tried?

Will you please take a measurement two feet from your LED and measure the 660nm wavelength with your passport? We would like to see the 660nm intensity of the Spectrum King!

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Here are some measurements at 440nm and 660nm from the California Light Works Solar System 550. Its a center measurement two feet beneath the fixture. Very impressive, the light controller is great. @david2 @nathan @jbohannan8 Final report on all ten LED participants will be ready this summer. Great results, very valuable for investors build facilities with LED lighting.


@Nate @Hunter @george @cirrusledgrowlights @jbohannan8 @david2 @nathan

Will you guys please share your thoughts on green light ? Why a LED manufacturer would include this 500-560nm portion of the spectrum? Is it more expensive or less expensive to manufacture pink or white light LEDs.

The research here suggests 660nm is key.


I actually don’t own a spectrometer. Sorry :grimacing: The image above should answer your question on intensity though no?

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Oh thats ok, Im curious if this Spectrum king measurement was taken two feet underneath the center. It looks like YPDF is around 1.5 for the spectrum king, 2.3 for the DE 1000w HPS, and 2.8 for the sun. The pink light LEDs really emphasize the red 660nm which is at 5.7 for the Solar System 550. Which draws 400watts.

What is the watt draw for your fixture? @david2 Have you ever tried a Lumigrow or Heliospectra?
There is also a company that is popular in Europe.

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I’m not a scientist or botanist but I love photosynthesis!

Here’s a good read on green spectrum


The SK600 draws 640 watts, Have not tried those other brands personally.


Thanks for sharing this article, very interesting. Japan is big on LED horticulture.You may find this interesting; There are studies here also that show green light increases biomass in lettuce, also from around 2009. I do question whether or not this is applicable to other crops like Cannabis for example? Its certainly a controversial topic. I appreciate your thought!


Do you feel that your LED is a improvement from HID?


The penetration is better with full white spectrum imo. my canopy depth used to sit higher up and not much bigger than 14"H . Currently seeing nice flower development way lower than that. take a look for yourself in this image.

Thats ^^ my first layer of trellis which has a total of 3 layers about a foot from the top of the pargro.
Here is another place to follow the progress of my garden :wink: all vegged and flowering under the Spectrum King LED using SmartBee Controllers. Are you familiar with SmartBee?