Question on proper blue light

So, @dbrn32 according to this article by Dr. Bugbee, the max blue should be roughly 5-10%. From the chart, I would imagine the HLG light has roughly 20-30%, but I could be totally off. Would it be possible to get some clarification on this if possible?

That’s an excellent question! I’m not sure I have a direct answer, but I’m happy to share my thoughts.

This discussion seems to be geared towards plants in general, and mostly about photosynthesis and some about cell division and stem elongation. For example, around 25 minutes into video Bruce says it’s not the energy but the number of photons that drive photosynthesis. This is deducting from importantance of small differences in light spectrum in favor of amount of photons. The plant responses to each wavelength and in combination of each other is a different story though.

When we start looking at cannabis the perfect light spectrum for photosynthesis is only a small portion of what we’re targeting. Thet talk about plant shape, and difference of plant growth. Those are directly correlated to final light recipe. Then we have terpene development and cannabinoid content to weigh against photosynthesis. All of this needs to be considered.

In the same breath he says mh lights are useless because hps is more efficient, and mh is great if you’re indoor and need short plants. So, all of it needs to bd taken with grain of salt imo.


Well damn, I would have thought that answer came from dr. Bugbee himself!
Thank you for taking the time to try to explain this, I am trying to get as much information on lighting as I possibly can, and there is just so much information out there!

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There is, and we’re constantly learning a lot. Most of the studies currently available focus on a single aspect like photosynthesis, cannabinoid content, or effects of a specific wavelength. Sometimes its important to weigh each against the other in terms of what you need. There is a definitive study suggesting UV wavelengths increase thc content. But the increase in test samples was from something like 20% thc to 21% thc. If that’s the best they can do, I don’t know if it’s something we all need to run out and buy. We may be able to supplement violet or blue wavelengths and see similar increases, or change something with our nutrient package.

Dr Bugbee is definitely fighting the good fight on our behalf. But I have yet to see a hands down best spectral distribution for cannabis from anyone. I think you’ll do more than good with hlg-650r though.


Nicely said, stoner!