The Ideal spectrum.

Old school grower

Active Member
Using 90CRI I haven't felt the need to supplement, but I've recently had an interest in UV. I have an area that would be perfect for a comparison grow so I think I'm going to work out a solution for lighting half of it with UV.
10 - 20 watts but not all day.
 

whytewidow

Well-Known Member
10 - 20 watts but not all day.
I use sonoffs to controll far reds and HE Photo red strips I had made. I run (10) 3k sammy strips and (5) 2700k sunboards with lm561c diodes. The strips I had made have 120 diodes. 60 of each alternated. I've done grows with jus the Sammy's. 3 and 27. Then I've done the strips on at lights out for the last 15 mins of the 12hr cycle. They got nothing but the reds. And now I've found that if the start of my 12hr cycle on the first 15mins is nothing but reds. To simulate sun rise. Sun peaking over the horizon is normally orangish/reddish. Then I leave reds on entire time. Then only reds on last 15 mins. To simulate sunset. Which is really heavy red in the spectrum. I've run the same strain over n over. Using the reds first 15 all day and last 15. Makes the plant produce way more trichs. It's actually visible with the eye. I would say trich production. Is atleast 20%- maybe more on the strain i run doing that way then not using the reds at all. It doesnt have a lot of trich production. But with the reds it puts out very nice trich production.


Edit: I wanna put some other moons in to run during the middle of the day. To see if it changes.
 

Old school grower

Active Member
I use sonoffs to controll far reds and HE Photo red strips I had made. I run (10) 3k sammy strips and (5) 2700k sunboards with lm561c diodes. The strips I had made have 120 diodes. 60 of each alternated. I've done grows with jus the Sammy's. 3 and 27. Then I've done the strips on at lights out for the last 15 mins of the 12hr cycle. They got nothing but the reds. And now I've found that if the start of my 12hr cycle on the first 15mins is nothing but reds. To simulate sun rise. Sun peaking over the horizon is normally orangish/reddish. Then I leave reds on entire time. Then only reds on last 15 mins. To simulate sunset. Which is really heavy red in the spectrum. I've run the same strain over n over. Using the reds first 15 all day and last 15. Makes the plant produce way more trichs. It's actually visible with the eye. I would say trich production. Is atleast 20%- maybe more on the strain i run doing that way then not using the reds at all. It doesnt have a lot of trich production. But with the reds it puts out very nice trich production.


Edit: I wanna put some other moons in to run during the middle of the day. To see if it changes.
I'm using a Storm controller for sunrise/sunset on the 3000k and 3500k cxm22's.
 

welight

Well-Known Member
In my experience 3000K 70CRI provided the best veg. Although I didn't use any 4000K spectrums I thought the 3000K 70CRI sample looked better than 3500K 80CRI. So I think 3000K 70CRI with added 660 would work quite well.

I didn't see the spectrum cited in the article. If you're right that would be some food for thought. Hopefully this thread will take off and we'll get citations with links and other relevant info.

What would be bad ass is a pre-built lamp with for instance 650 PPF of 4000K 80CRI and a separate channel with 350 PPF of 660nm and a third channel with 730. Onboard circuit automatically keeps the 730 on for 15 minutes past lights out. Manually select whether phosphor only or phosphor + monos.

Whether these sunlight spectrums will prove themselves in the long run I don't know. I don't suspect sunlight is the best just because plants evolved under it. Nature does the best with what it's got, but it would be a mistake to assume the spectrum can't be improved artificially especially from an efficiency perspective. The data seems to be indicating sunlight isn't the best in that regard, but I'm open to seeing results that suggest otherwise.
Been messing with the concept as well first 5050 boards we build are 3000k 70 CRI with the Cree 660, the red certainly pulls on the spectrum dropping the total spectrum by nearly 300 Kelvin and does improve CRI and shows the SPD power of the red, but is difficult to get blended phos/non phos leds to have a big impact on CRI, When we tested Nichia Optisolis and used two spectrums and the right ratio, we improved the CRI from 97 to 99.4, and had similar results mixing non phos Cree XPE leds. It all depends on how important you see CRI relative to photons re grow stage

Parameter Value
CCT 2757 K
Duv -0.0019
CRI (Ra)(R1~R8) 80
CRI (Re) (R1-R15) 74
CQS 77
TLCI(Qa) 57
GAI 55
TM-30-15 Rf 74
TM-30-15 Rg 103
Illuminance 33,940 lux
Foot Candle 3,153.2 fc
PPFD (400-700nm) 537.01 µmol/m2s
 
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Rahz

Well-Known Member
Been messing with the concept as well first 5050 boards we build are 3000k 70 CRI with the Cree 660, the red certainly pulls on the spectrum dropping the total spectrum by nearly 300 Kelvin and does improve CRI and shows the SPD power of the red, but is difficult to get blended phos/non phos leds to have a big impact on CRI, When we tested Nichia Optisolis and used two spectrums and the right ratio, we improved the CRI from 97 to 99.4, and had similar results mixing non phos Cree XPE leds. It all depends on how important you see CRI relative to photons re grow stage

Parameter Value
CCT 2757 K
Duv -0.0019
CRI (Ra)(R1~R8) 80
CRI (Re) (R1-R15) 74
CQS 77
TLCI(Qa) 57
GAI 55
TM-30-15 Rf 74
TM-30-15 Rg 103
Illuminance 33,940 lux
Foot Candle 3,153.2 fc
PPFD (400-700nm) 537.01 µmol/m2s
I'm surprised with that 660 spike the K only dropped as much as it did. Looks like around 8% of par between 400-500nm which I guess is about where 2700K should be. Very nice. I don't consider CRI important except as a general way of characterizing phosphor only SPDs.
 

welight

Well-Known Member
I'm surprised with that 660 spike the K only dropped as much as it did. Looks like around 8% of par between 400-500nm which I guess is about where 2700K should be. Very nice. I don't consider CRI important except as a general way of characterizing phosphor only SPDs.
Yes, as I said the blending of phos and non phos leds does not typically give you a complete blended solution
 

Rahz

Well-Known Member
I attempt to try to match my spectrum to the action spectrum more then the absorption spectrum of the McCree curve.
I think it's worth testing. A few concerns.

Most chlorophyll A/B charts show stronger response to blue than red, which doesn't show up in whole leaf response.

There's clearly some strong photosynthesis going on in most plants between 570-600nm that doesn't seem to be directly related to chlorophyll A/B. If it is related then it seems like the difference has something to do with the preparation. I.E. whole leaf -vs- grinding a leaf up and straining the chlorophyll out.

In the OP, the pic I put together suggests phycoerythrin is responsible for that action. It's an accessory pigment to chlorophyll A. Problem is, I can't find any information suggesting it has been isolated in plants.

If chlorophyll AB preparations are excluding all other photoreceptors this would explain why the AB action spectrum is so different from the Mcree curve.

But if phycoerythrin isn't present in plants, what could account for the strong response for most plants in the 570-600 range?
 
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jarvild

Well-Known Member
That's just it the testing from my understanding is for photosynthesis. That's only one process of many that occur in the plants.
 

Rahz

Well-Known Member
That's just it the testing from my understanding is for photosynthesis. That's only one process of many that occur in the plants.
Agreed. Some photoreceptors don't seem to play a part in photosynthesis, but the ones that do are accessory pigments that fuel chlorophyll. This being the case, the question is whether a mixed spectrum is more efficient than direct stimulation of chlorophyll. The Mcree study seems to suggest plants are more efficient with accessory pigment stimulation. It's just an assumption on my part, but that's the only easy explanation.

Phycocyanin has also (as far as I can tell) only been isolated in algae. This is the crux of the mystery. Any time I research accessory pigments in plants I see information on lycopene, carternoids, etc. which are all primarily active in the presence of blue light.

I can guess, looking at the Mcree curve that there are specific accessory pigments responsible for the 600-620nm peak. The phycoerythrin and phycocyanin peaks match up so well with Mcree it's logical to suggest that's exactly what's going on, but I've been unable to verify it so far. Still, unless we want to totally discount Mcree, it might be smart to focus on the 600-620 range and supplement with blue/deep red/etc. in whatever amounts are optimal.
 

Old school grower

Active Member
I think the majority of us seasoned growers realize that the science is still lacking in the knowledge of plant physiology.
Oh the science is definitely lacking. Leaving us no choice but to experiment. Mj requires certain nutrients at certain stages of growth. Lighting should be no different. Not just 3500k- 4000k veg and 2700k-3500k flower but more tailored and even strain specific.
 

jarvild

Well-Known Member
Oh the science is definitely lacking. Leaving us no choice but to experiment. Mj requires certain nutrients at certain stages of growth. Lighting should be no different. Not just 3500k- 4000k veg and 2700k-3500k flower but more tailored and even strain specific.
Considering, most of us growing hybrid cultivars, that originated from crosses with land-race cultivars, varying from different regions of the word that could be a time consuming process. The original Gene pool is already diluted enough.
Not to mention that a lot of our cultivars have been developed under artificial lighting and are plants are rather remarkable at adapting fairly quickly to their environment.
 

Old school grower

Active Member
Considering, most of us growing hybrid cultivars, that originated from crosses with land-race cultivars, varying from different regions of the word that could be a time consuming process. The original Gene pool is already diluted enough.
Not to mention that a lot of our cultivars have been developed under artificial lighting and are plants are rather remarkable at adapting fairly quickly to their environment.
True but if you grow the same strain long enough you'll know/learn what they like and when.
 
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