Reds: What is needed to supplement/enhance a full-spectrum white?

tstick

tstick

Well-Known Member
Is there a "formula" for how much red (and what exact color red) is best to enhance a full-spectrum white COB fixture such as a CXB3590 4000K COB fixture? And if the full-spectrum fixture produced "warmer" white light -such as a 3500K or a 3000K, how would I need to adjust the red accordingly?

I have 4 4000K CXB3590's and drive them hard (@100watts each)...What would be a worthy amount of red enhancement? And what reds...660...730...etc.?

Should I apply the red enhancement right along with the full-spectrum whites on the same on/off schedule? Or, should they come on later in the cycle and then past when the whites go off (so as to mimic the setting sun, etc.?)

Also....Can too much red be added that would produce an unwanted effect? If so, then please explain.

Sorry for all the Q's! I want to add some reds...but want to make sure I do it properly!

Thanks
 
Airwalker16

Airwalker16

Well-Known Member
tstick said:
Is there a "formula" for how much red (and what exact color red) is best to enhance a full-spectrum white COB fixture such as a CXB3590 4000K COB fixture? And if the full-spectrum fixture produced "warmer" white light -such as a 3500K or a 3000K, how would I need to adjust the red accordingly?

I have 4 4000K CXB3590's and drive them hard (@100watts each)...What would be a worthy amount of red enhancement? And what reds...660...730...etc.?

Should I apply the red enhancement right along with the full-spectrum whites on the same on/off schedule? Or, should they come on later in the cycle and then past when the whites go off (so as to mimic the setting sun, etc.?)

Also....Can too much red be added that would produce an unwanted effect? If so, then please explain.

Sorry for all the Q's! I want to add some reds...but want to make sure I do it properly!

Thanks
Click to expand...
Well 730 is far red and that's only for 15 mins at end of 12/12 cycle.
 
Airwalker16

Airwalker16

Well-Known Member
As far as I know, there's no particular nm mainly because the exact # most likely isn't made in an led. So we get as close as possible. 630-660nm for redd and 420-459 for the blue.
 
tstick

tstick

Well-Known Member
Airwalker16 said:
As far as I know, there's no particular nm mainly because the exact # most likely isn't made in an led. So we get as close as possible. 630-660nm for redd and 420-459 for the blue.
Click to expand...
But, as described in my scenario, the (4 CXBs @ 4000K each) would already produce enough blue...right?
 
Rahz

Rahz

Well-Known Member
Going by the Mcree curve, everything between 580 and 680nm has 80+ percent absorption rate.

To avoid monos, going with a lower K 90CRI option like 3000K/90CRI or 2700K/90CRI would be ideal. If using something like 4000K where monos will be beneficial then it would be best to add 660nm. The mid point of the +80 range is 630, but the actual peak occurs at 665-670.

I haven't experienced it myself but too little blue will result in spindly growth and perhaps some stretching. I actually like the morphogenesis at 3000K 80CRI so it should be difficult to screw up a build using 4000K white source. As long as the percentage of blue is +10 percent you should be good.

When I have the time I've been working on a spectrum rating standard, similar to YPF but isn't a measure of flux, just a way to rate a spectrum weighted by the Mcree curve. It won't provide a perfect profile, and would register highest with pure 670nm light, but it will be a good way to compare any two white spectrums to see which will promote the most photosynthesis.
 
Yodaweed

Yodaweed

Well-Known Member
Airwalker16 said:
As far as I know, there's no particular nm mainly because the exact # most likely isn't made in an led. So we get as close as possible. 630-660nm for redd and 420-459 for the blue.
Click to expand...
680nm is deep red, many LED makers use them. Mainly you want 660nm and 680 diodes for red supplementation.
 
JorgeGonzales

JorgeGonzales

Well-Known Member
churchhaze said:
Has anyone yielded better supplementing with 630-680nm or is everyone just going based on theory?
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I think the answer is "sort of?" and a noncommittal shrug.

@nevergoodenuf did a 4000K 80CRI vs 3200K 95CRI shootout. Correct me if I'm wrong nevergood, but I believe the 95 CRI was the cheaper and less efficient COB in that comparison.

Anyway, yield was identical, but larf was less with the 95CRI, and it had a hair more of everything in the lab results. That's all I got, but it's the closest thing I've seen to a proper side by side.
 
Rocket Soul

Rocket Soul

Well-Known Member
Having seen @Malocan test out: what nm gets blocked after 1/2/3 leaves, or what tge light spectrum looks like deeper into tge cannopy i would go for deep reds, 680nm, maybe even intracannopy if i could.
 
CobKits

CobKits

Well-Known Member
i feel like it will be a while before we see a really good study, there are just so many variables you really need a large sample size under carefully controlled conditions to draw solid conclusions. at this point it appears 2700k-4000k in 70-90 cri all produce good results but again a lot of that is just pure photon delivery. even bugbee concluded that # of photons was a larger factor than spectrum which is why we see 3500 and 4000K popular even though 3000K is probably the more "ideal" spectrum, as the 3500k and 4000k crank out 5-15% more photons.

looking at the digitized data from @alesh , @JorgeGonzales, etc, the actual photon delivery between colors is not as pronounced as one would think. its liek the old saying, nothings free and at some point youre working with the limits of the dies themselves, and hope that the phosphors put the photons where you want them
 
M

mypassion

Well-Known Member
How about mixing different K cob's, different CRI?

... I bet there is a thread about this that I can't find?
 
C

churchhaze

Well-Known Member
Tweaking spectrum toward the red just to get a higher umol/s is exactly why I think umol/s is a misleading measurement. Of course the same thing is true for watts, but with blue. Should we all grow with pure 660nm for ultimate photon flux?
 
Malocan

Malocan

Well-Known Member
ReddEyez said:
What are your guys thoughts on adding these to a 660nm and 730nm supplemented cobs?
http://www.stevesleds.com/SemiLeds-DEEP-InfraRed-IR-3W--Brand-NEW_p_309.html
http://www.stevesleds.com/SemiLeds-InfraRed-IR-3W--Brand-NEW_p_268.html

Great thread! Tons of experimenting with supplementation. Thanks Positivity :joint:
https://www.rollitup.org/t/diy-led-grow.738671/
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Hi,
im not sure, i think it wouldnt make much sense to use them, only if you want more heat in your grow room.
But im not sure, im no expert.

Guod shared a nice PDF, i will link it. According to this pdf(page16/36) it make no sense to use them.
http://horticulture.ahdb.org.uk/sites/default/files/u3089/Lighting_The-principles.pdf
 
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ReddEyez

ReddEyez

Well-Known Member
nevergoodenuf

nevergoodenuf

Well-Known Member
JorgeGonzales said:
@nevergoodenuf did a 4000K 80CRI vs 3200K 95CRI shootout. Correct me if I'm wrong nevergood, but I believe the 95 CRI was the cheaper and less efficient COB in that comparison.

Anyway, yield was identical, but larf was less with the 95CRI, and it had a hair more of everything in the lab results. That's all I got, but it's the closest thing I've seen to a proper side by side.
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Actually, the high CRI cost more, but not worth the extra cost, in my opinion. I used a lux meter to compare the 2 at around 18" and there was a 30,000 to 40,000 lux difference, but they grow equally if not a bit better. When I can get my hands on the 3500k 90cri, I will possibly use them, since there is no price difference. I also like the balance of blue to red.
I know this isn't scientific, but when you look at Citizens PPF/A-PPF charts and you average the 2, the higher cri looks better.
It could have been the extra stretch that caused less larf, I don't know. I may do this test again, but running a different strain and run them at 250 watts each. I just got 2 Dream Queens, so after a couple clones can be cut, I will try to get that started.
 
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