Red light best for budding?

curious2garden said:
You always make me think and learn something. I love that. I finally changed my grow room over to LED! This is my new flower light's spectrum. It's an HLG Scorpion Diablo X. My plants are loving it compared to my old HPS. It's sure been a learning curve LOL. But the plants have really responded.
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my attis almost the same
 
Delps8 said:
Perhaps, due to the "blue photon penalty".

There's a measurable and significant decrease in crop yield when the percentage of blue photons hitting a grow exceeds 4% in flower. At 20%, the penalty is ≈ 15% loss (going from memory)

[time passes]

The title of the paper that describes is "Cannabis lighting: Decreasing blue photon fraction increases yield but efficacy is more important for cost effective production of cannabinoids" and, when you search in Google, the summary reads "Yield increased by 0.77% per 1% decrease in blue photons". The paper is by Dr. Bruce Bugbee and some of his students. Bugbee is a leading, arguably "the leading", expert in cannabis grow lighting and is also well renowned for his decades of experience in plant nutrition.

This research was not a breakthrough discovery.; its value is that it quantified the impact. We've known that plants grow compact and bushy when their light has a lot of blue photons while plants getting light with a lot of red photons will grow taller. That's one reason why cannabis growers used different lights over the course of a grow.

What model Vipar are you using?
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sorry for the late reply..had computer issues...i'm using a pair of vipar spectre Par 450. each has white, red and blue light with individual controls.
 
grotbags said:
if the following spectrum is correct then i wouldnt be running the blue at all in flower, 50% blue?...

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Yes. That fixture generates very little light so you need every photon that you can get.

The graphic that look like a bulls eye is called a "PPFD map". PPFD is the acronym for how many light particles ("photons") are hitting a given area (one square meter) in one minute. At the very center, it generates 560 µmols ("micromoles"), at 1' it's ≈ 415µmols, and in the corners it's 34µmols. I would describe that lightcast as having a significant hotspot in the center with PPFD readings collapsing after 6" off center.

Plants grown under low light levels like this will tend to be tall with very little inflorescence (stems and leaves). The very high amount of blue in the spectrum will tend to offset that because blue encourages the growth of compact bushy plants but yield will suffer because there are so few photons hitting such a small area. A plant under that light simply isn't getting much food. Remember - light is what a plant uses to make food via photosynthesis.

In contrast, early this year, Vipar came out with their XS 1500 Pro (I have an earlier model, the XS 1500). When I saw the PPFD map, my jaw dropped - in a word it is "superb" and it's only $99. Vipar has run with this product. It's an absolute steal for the 2' space and they're selling them in pairs as an incredibly inexpensive solution for lighting a 2' x 4'.


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If you continue to use this light, move your plants directly underneath the light and lower the light to about 18" above the canopy ("hang height"). Check with the manufacturer about their recommendations for hang height and go with what they recommend.

An alternative is to retire this light and get the Vipar XS 1500 Pro. I've seen for sale for $100±. It's an absolute steal at that price and you will end up with a significantly better outcome.
 
grampanew2this said:
sorry for the late reply..had computer issues...i'm using a pair of vipar spectre Par 450. each has white, red and blue light with individual controls.
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Refer to my other posting re. the hot spot.

Lighting a grow with this light is a bit of a dance because you'll have two hot spots so you'll have to be careful where you position the light. The PPFD map says 840µmols at 18". The "light saturation point" for cannabis (in ambient CO2) is 800-1000µmols meaning that cannabis, generally speaking, can't use more light than that. That means your plants will be getting about as much light as they can handle but, because of the hot spot, they're only getting that much light directly underneath the light.

If you want to get "lotsa cannabis", buying a different light will save you a lot of time and headache of trying to "get the light right". If you're in a 2' x 4', Vipar is selling a set of XS 1500 Pro's for $170±. That's an excellent value. Another option is the growlightscience.com Progrow 3200. They've been around for a few years and, until recently, I was no fan of their products. The 3200 changed all of that. The PPFD map is the best I have seen in a grow light and it's got the same spectrum as my $650 Growcraft X3 flower light. If I were buying a light for my 2' x 4' tent today, I'd probably buy the Progrow instead of the Growcraft.

On the other hand, if you don't want to put any more $$ into your grow, dial back your expectations, and use the manufacturer's recommended hang height.
 
Moflow said:
Look at the differing blues in these pics.
Which spectrum is best for flowering?
Confused.com lol

Hlg Diablo
View attachment 5324040

Hlg Scorpion
View attachment 5324041

Hlg blackbird
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Scorpion B spec
View attachment 5324044

GLA
View attachment 5324045

Lumatek Attis
View attachment 5324046

Mars hydro
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"best" is a word that's, usually speaking, "best" avoided because, one, it's not defined and, since it's not defined, defining what "best" means that defining it can become the focus of the discussion rather answering the question.

The Grow Lights Australia spectrum looks excellent as an all round spectrum. I first saw that maybe two years ago and was really impressed - it certainly covers the bases in terms of providing light in the ePAR range so congrats to GLA for pushing the envelope in that respect. By that I mean that I haven't seen any other light vendor do anything like GLA in terms of incorporating different wavelengths to their fixtures. It's a risk - research cost and for "straying outside the markers" in terms of spectrum - but they took the leap.

Back to the "best" flower spectrum. HLG uses "R" to denote a flower spectrum with the heavy red component while their "B" lights are so labeled because of the heavy blue weighting and those are labeled for using during veg. The lights from Lumatek and Mars are variations on a balanced spectrum. The Diablo looks to be a "balanced" spectrum. Setting those aside, I like the Scorpion because it has incorporated some red in the 730 range but the spectrum from either the Scorpion or the Diablo would be my pick.

IRL, what is my pick?

I went with lights with the spectra shown below and things have worked out well. Chilled (Growcraft) and HLG are the only companies that I know of that make separate veg and flower lights. HLG products never did anything for me - board light with a monster hot spot - so I went with Growcraft*.

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Interestingly, the folks at GrowLightScience thought so highly of the flower spectrum for the Growcraft that they have decided to create a vey similar spectrum across their entire product line.

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One of the mods at a site that's dedicated to autoflowers (I'm assuming I can't post the name), uses the Growcraft flower light + a Rapid LED blue puck through the entire grow and gets excellent results.


*My veg light only has two light bars so I use a Vipar XS 1500 (not the Pro) and a Rapid LED blue puck in seedling and flower and will use he XS 1500 and a Mars SP 3000 throughout the grow to add spot lighting. For one grow, I ended up with 450-500 watts lighting the grow (in a 2' x 4') but it was a very large plant that yielded something like 880 gm/m2.
 
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Delps8 said:
I went with lights with the spectra shown below and things have worked out well. Chilled (Growcraft) and HLG are the only companies that I know of that make separate veg and flower lights. HLG products never did anything for me - board light with a monster hot spot - so I went with Growcraft*.
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growcraft make a high quality light no doubt (and so they should cause they arnt cheap), but their spectrums are unremarkable.
its the same spectrum everyone uses who chase efficiency first and foremost. roughly 4k white plus as many 660nm as they can afford to cram onto the pcb. the only reason they use so many 660nm is to increase the efficiency to get over the 3 umol/j headline. they dont use them because they think the are good for flowering, if the most efficient mono was say 590nm they would use a shit ton of them instead and you wouldnt see 660nm on 99% of growlights.

Delps8 said:
Interestingly, the folks at GrowLightScience thought so highly of the flower spectrum for the Growcraft that they have decided to create a vey similar spectrum across their entire product line.
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i highly doubt growlightscience looked at growcrafts flower spectrum and decided to copy it because they were so impressed by it.
its quite litterally the only spectrum you can more less choose to get good efficiency (this has changed slightly recently with the introduction of samsungs mint evo being used instead of or in conjunction with standard high efficiency whites).
if you added more 660nm monos to that mars hydro spectrum it would be exactly the same as the growcrafts flower spectrum.
 
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I got a couple of boards in this spectrum below from r2thk on Alibaba 3 - 4 years ago now.
So someone was thinking outside the box back then.
512 leds, old school LM561C's and Epistar.
I only use them in my flower area along with other lights and plants only go under them after 4/5weeks of flowering in another area.
I do have other lights, spectrums. R Spec, 3000K, 3500K, 4000K , UVa etc.




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Moflow said:
I got a couple of boards in this spectrum below from r2thk on Alibaba 3 - 4 years ago now.
So someone was thinking outside the box back then.
512 leds, old school LM561C's and Epistar.
I only use them in my flower area along with other lights and plants only go under them after 4/5weeks of flowering in another area.
I do have other lights, spectrums. R Spec, 3000K, 3500K, 4000K , UVa etc.




View attachment 5324072
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yep at least it looks like they were thinking of what they could do to improve/fill out the spectrum, a little less blue 450nm and it already looks more appealing than a lot of spectrums you see on modern lights.
 
grotbags said:
GLA first no question, then hlg scorpion second. the rest are meh.
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I was able to finally set up my small 2x2.5ft tent and hang up my GLA original highlights boards once again. Not the most experienced grower, but these lights seemed to serve me better than the 3500 80 cri cobs I had used previously. Not quite as "advanced" as their newer boards but I still think they offer a bit fuller spectrum than the standard options.

Here's the spectrum just to add to the mix we have going in this thread already..

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Delps8 said:
You can do that math but grow light efficiency is usually reports in μmole/J.
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The report posted measures electrical power and radiant power(how much actual light in watts) which at least gives you a ratio of power in, power out. This is the way most leds are measured and reported. Of course would be a lot better if the report Mo posted actually gave ppf/w but it doesnt allow you to calculate that in an easy way, if you know how youre welcome to stab at it. However knowing this light is around 15% efficient and modern white based leds are about 60% (for a decent growlight) at least gives op some information; he could literally quadruple light/w using a newer 100ish $ light.
 
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