Bluer light in flowering?

Advanced Techniques
#1

I’ve seen a great emphasis in use of red (615-660nm) in flowering, but studies suggest better stoma action (big deal for those of us who use CO2 and oxygen supplementation) in bluer spectrums, so why is the ideal level of blue light at around 60%? That isn’t even reflected in the McCree spectrum. As long as the 660 spike is there, photosynthesis should be near equivalent on both ends. Bonus, tighter internodes and denser buds…

Source: The effect of wavelength of light on stomatal opening - PubMed

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#2

From what I have read(mainly about full spectrum led grow lights) the ideal spectrum mainly blue then red and very little green and yellow, similar to the Sun, thats why “blurple” grow lights are inferior, some of the spectrum is missing. Its a bit like giving your plants only macro and no micro nutrients, they’le grow but not well.
This is only my assumption and would love to know more, along with all aspects or growing.

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#3

My understanding so far is that green light penetrates like crazy (and has relatively high par ratings) and yellow light causes heat. I’m incorporating white because of it. Minimum heat given CO2 use, maximum penetration. I’m going to price things out tonight. It’s a 4x4 sealed space, so it’s whatever I want.

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#4

I’m working on my light. Can’t prototype the spectrum I want because the UVB emitters are ridiculously priced, but for the time being, this is the array (x13) that I’m pricing out.

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#5

according to Dr. Bruce Bugsby Green light penetrates the leaf better then blue, for better photosynthesis
but I have also read that to much blue during flower, may induce the plant to concentrate more on veg then flowering

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#6

My goal was a 8.5:10 blue:red balance and I think I nailed that pretty well. Can’t say enough good stuff about the Luminus tool. Lumileds has one but it’s laggy, buggy, and kinda sucks in comparison.

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#7

Might double the UV emitters since UVA isn’t as dynamic for the plant as UVB, too.

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#8

I heard a guy say he likes to swap back to his mh light the last two weeks of flowering. I forgot what his reason for this was, he had it going on though! Sorry I wish I remembered more… lol.

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#9

MH makes them crystal on up from the greater uv output over hps. When I was running all HID I would do a 2:1 ratio of MH: HPS in veg, then flip in flower. It did an amazing job compared to when I started and did only MH in veg and only HPS in flower.

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#10

I hadn’t heard that on stomata opening. The abstract you link to says red is better than blue. Blue causes less stretching.

I think historically HPS are simply the most efficient HID lights, and that is more important than spectrum.

#11

You was jumping bro! You got any pictures from those grows? I have been experimenting with cmh with hps and a couple timber rigs… the nuggets under the cmh almost always are a little bit better. I don’t know why, but I like it.

#12

No I don’t, that was 8-11 years ago. I had to pack up all my stuff for a few years too in-between.

#13

I heart cmh

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#14

Red is only better in a nitrogen rich environment. The internodal spacing is reduced as well as enhanced stoma action by the blue light. Again, super important if you’re running supplemental CO2. Tighter internodes can translate to tighter bud formation, giving you denser bud structure.

#15

The answer to the experiment is to use s programmable full spectrum led fixture, but they cost megabucks.:confused:

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#16

You could always mix and match and learn how to wire dimmers. Between Cutter and Digikey, one could conceivably accomplish anything regarding lighting. Cutter even carries the new white Cree 2835’s with legit red peaks on linear strips. The price could be better, but considering the options between the two, the outcome is likely worth it.

#17

My mantra since the early 2000’s has been:

If you CAN diy, diy.

If you CAN’T diy, LEARN TO DIY.

Fact is, there aren’t many companies out there who will give you a fair shake. Medic Grow may be the only lighting company who is an exception, but exclusively for their base model Fold 8. Everyone else is relying on laziness and ignorance to make money, and if I’m building a light that suits me for 85% of the price of the same prebuilt, then I’m doing it. Fuck a warranty. Build it yourself and you’ll know how to fix it yourself. Scale up your grow, increase your magnitude, and that 15% savings is non-negligible as fuck. Same goes for hydroponics layouts. Why would I spend THAT much on an Undercurrent system from Current Culture when it’s less than half the price to diy? They list the fuckin parts even. Frankly, at this stage in the game, it’s embarrassing to buy prebuilt.

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#18

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Also, for reference…there are more pigments and absorption spectra than just chlorophyll a and b and beta carotene. My ultimate goal is to hit every single one of these peaks in proportion. All that’s stopping me is a multiple output DALI power supply, integrating sphere, and ridiculously expensive spectroradiometer. :roll_eyes:

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