4000K 90cri

crimsonecho

Well-Known Member
i may want to build a bar type cob powered fixture using 3x 2m long heatsinks and 36 cree cobs (12 per bar). 215w per bar 645w total driven at 500ma.

now what are your opinions on this spectrum? this is a new cob series to me i just came by it yesterday and the 4000K 90cri seems interesting (dark green on the chart).

i’d appreciate your thoughts on the subject @coreywebster @Rocket Soul @Kassiopeija and everyone else i forgot to tag.
 

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Rocket Soul

Well-Known Member
i may want to build a bar type cob powered fixture using 3x 2m long heatsinks and 36 cree cobs (12 per bar). 215w per bar 645w total driven at 500ma.

now what are your opinions on this spectrum? this is a new cob series to me i just came by it yesterday and the 4000K 90cri seems interesting (dark green on the chart).

i’d appreciate your thoughts on the subject @coreywebster @Rocket Soul @Kassiopeija and everyone else i forgot to tag.
Thats a narrowband high cri phosphor, similar to one of the diodes in the GLA boards. When you compare this to another 90 cri chip it will most likely have more lum/w but its fairly equal if you compare ppf/w.

This link might be helpfull for that type of comparison as they have done both lum/w and ppf/w measurements:



When taking into account the actual photon count/w they look less efficient than when looking at lum/w; its basicly your standard 80cri spectrum with some narrow peaks in the red part of it.

Ive not seen this grow on its own so i cant really be in favor or against it. I know GLA added it to the mix in order to target the chloro absortion peak around 630nm. But they also added 660,730 a d 405nm.

Id love to see it grow but for flower i would probably opt for a lower cct (2700-3000k) of standard 90cri phosphor, it adds a bit of red everywhere including far red which seems like a safer bet. Are you thinking you might add any monos to this?
 

crimsonecho

Well-Known Member
Thats a narrowband high cri phosphor, similar to one of the diodes in the GLA boards. When you compare this to another 90 cri chip it will most likely have more lum/w but its fairly equal if you compare ppf/w.

This link might be helpfull for that type of comparison as they have done both lum/w and ppf/w measurements:



When taking into account the actual photon count/w they look less efficient than when looking at lum/w; its basicly your standard 80cri spectrum with some narrow peaks in the red part of it.

Ive not seen this grow on its own so i cant really be in favor or against it. I know GLA added it to the mix in order to target the chloro absortion peak around 630nm. But they also added 660,730 a d 405nm.

Id love to see it grow but for flower i would probably opt for a lower cct (2700-3000k) of standard 90cri phosphor, it adds a bit of red everywhere including far red which seems like a safer bet. Are you thinking you might add any monos to this?
thanks for your input man i see the link you have provided but i have no reference point for standard cree 3000Ks or 4000Ks umol/j-wise. still this spectrum doesnt look particularly bad for growing does it?

now that was my initial instinct too. since it hits that 600-640 gap with higher intensity i’m feeling this might not be particularly bad for growing flowers.. and for the reason it peaks at those levels and lacks the higher intensity blues compared to standard 4000K crees i thought it may not be worst idea to run them for flowering. i also like a little bit of blue in my flowering spectrum for denser buds and compact growth.

now i was thinking of using these alone but throwing around the idea of adding monos too. a little bit of fr/ir and 380-400 might do good for this spectrum imho but i also dont want to complicate my design too much. i used to have this 3 bar design with 18 3000K 90cris and they worked very well. now bc i’m planning on moving out of tents and want to build scrog frames in nonstandard dimensions not many plug and play fixtures fit my application needs and i really liked how cobs grow.

now i still have some of those 3000K 90cris laying around from my last diy like 4 years ago. i think i got 12 or something which i can incorporate into the design but tbh i really want to give these a go because they are just new to me with better chloro peaks.

you are right these do have a higher lumen output compared to standard 80cri 4000K but i dont know how to interpret that as i dont have a umol/j value for a standard 4000K. you think these will offer less umol/j than those standard 4000K 80cri cree diodes?
 

Rocket Soul

Well-Known Member
thanks for your input man i see the link you have provided but i have no reference point for standard cree 3000Ks or 4000Ks umol/j-wise. still this spectrum doesnt look particularly bad for growing does it?

now that was my initial instinct too. since it hits that 600-640 gap with higher intensity i’m feeling this might not be particularly bad for growing flowers.. and for the reason it peaks at those levels and lacks the higher intensity blues compared to standard 4000K crees i thought it may not be worst idea to run them for flowering. i also like a little bit of blue in my flowering spectrum for denser buds and compact growth.

now i was thinking of using these alone but throwing around the idea of adding monos too. a little bit of fr/ir and 380-400 might do good for this spectrum imho but i also dont want to complicate my design too much. i used to have this 3 bar design with 18 3000K 90cris and they worked very well. now bc i’m planning on moving out of tents and want to build scrog frames in nonstandard dimensions not many plug and play fixtures fit my application needs and i really liked how cobs grow.

now i still have some of those 3000K 90cris laying around from my last diy like 4 years ago. i think i got 12 or something which i can incorporate into the design but tbh i really want to give these a go because they are just new to me with better chloro peaks.

you are right these do have a higher lumen output compared to standard 80cri 4000K but i dont know how to interpret that as i dont have a umol/j value for a standard 4000K. you think these will offer less umol/j than those standard 4000K 80cri cree diodes?
Id expect them to offer a bit less ppf/w than a standard 4000k 80cri. High cri red phosphors are generally less ppf-efficient than than standard phosphors.
I dont really think these chips have a much lower blue level than standard 4000k i think its more an effect of scaling of the image; with really sharp spikes like that on top of a standard(ish) 80 cri spectrum everything which isnt a peak looks somewhat diminished. Compare the blue peak to the green bump; youll find that they are pretty much similiar in height/intensity, just as a standard 4000k 80 cri. So the reduced blue may be a trick of the eye.

My general thinking right now for flower goes in the direction of high red, low green low blue on the main channel, then a separate channel for wide blue and uv. Maybe even far red on a separate channel. Weve got a couple of fixtures hanging now evaluating were we wanna go in the future as we need to update some lights but sadly i dont have full conclusions regarding this, need a few more grows to have a clear picture.


Right now we have GLA strips versus plain white 3000k but also in the same grow space another fixture of 2700k 90cri + 660 and a second channel of uv (2:1 400/365nm about 10 % of total draw). This light kicked out some pretty kickass weed but still not been able to compare the results with the GLA strips.

In the same space we also have another light based on a pretty standard HE spectrum (4000k 80 cri + 660nm). We added far reds, uva in same proportions and even uvb 295nm. The result was somewhat lack luster although it yielded quite well. But it didnt have the high or the smell or the taste of that 2700 tray. My theory is that the higher green content in this light may have erased any perceptable benefit of the added uv; green seems to have this antagonistic relationship to blue, its documented somewhere with regards to general botanics but i dont know where, messy quoter :) . Dont have any canna related info on this but i have a hunch at least based on general.

Please dont base your decisions only on my ideas since they are far from complete, im still trying to evaluate if or how much yield loss the uv may cause.



If you want to evaluate differences between standard 90cri and this spikey 90cri type spectrum: we have measurements of both in the 2700k range between here and led tech web:

To my very cursory glance they look very similar in ppf efficiency; the values are very comparedable since both eb and led techs strips are based on 7diode strings: you can pretty much compare 700mA to 700mA on each side.

Not sure if it what you were looking for since youre looking at 4k but i cant really see these chips have much of a secret sauce in them by looking at numbers. Please tag me for your grow if you end up going forward with these.
 

crimsonecho

Well-Known Member
Id expect them to offer a bit less ppf/w than a standard 4000k 80cri. High cri red phosphors are generally less ppf-efficient than than standard phosphors.
I dont really think these chips have a much lower blue level than standard 4000k i think its more an effect of scaling of the image; with really sharp spikes like that on top of a standard(ish) 80 cri spectrum everything which isnt a peak looks somewhat diminished. Compare the blue peak to the green bump; youll find that they are pretty much similiar in height/intensity, just as a standard 4000k 80 cri. So the reduced blue may be a trick of the eye.

My general thinking right now for flower goes in the direction of high red, low green low blue on the main channel, then a separate channel for wide blue and uv. Maybe even far red on a separate channel. Weve got a couple of fixtures hanging now evaluating were we wanna go in the future as we need to update some lights but sadly i dont have full conclusions regarding this, need a few more grows to have a clear picture.


Right now we have GLA strips versus plain white 3000k but also in the same grow space another fixture of 2700k 90cri + 660 and a second channel of uv (2:1 400/365nm about 10 % of total draw). This light kicked out some pretty kickass weed but still not been able to compare the results with the GLA strips.

In the same space we also have another light based on a pretty standard HE spectrum (4000k 80 cri + 660nm). We added far reds, uva in same proportions and even uvb 295nm. The result was somewhat lack luster although it yielded quite well. But it didnt have the high or the smell or the taste of that 2700 tray. My theory is that the higher green content in this light may have erased any perceptable benefit of the added uv; green seems to have this antagonistic relationship to blue, its documented somewhere with regards to general botanics but i dont know where, messy quoter :) . Dont have any canna related info on this but i have a hunch at least based on general.

Please dont base your decisions only on my ideas since they are far from complete, im still trying to evaluate if or how much yield loss the uv may cause.



If you want to evaluate differences between standard 90cri and this spikey 90cri type spectrum: we have measurements of both in the 2700k range between here and led tech web:

To my very cursory glance they look very similar in ppf efficiency; the values are very comparedable since both eb and led techs strips are based on 7diode strings: you can pretty much compare 700mA to 700mA on each side.

Not sure if it what you were looking for since youre looking at 4k but i cant really see these chips have much of a secret sauce in them by looking at numbers. Please tag me for your grow if you end up going forward with these.
thanks for the charts and info. yes this scaling with spectral charts confuses me terribly. now i checked both numbers and yes they do look identical i wish they posted a wavelength distribution chart as you have posted.

so you are saying from quality point of view you’d personally consider going with 2700K with added uv and 660.

there is also 3000K on the chart i posted (the red line) do you think those spikes could help shift wavelength distribution to more orange red thereby increasing the intensity of red light compared to a standard 3000K? (hence also lowering the intensity of greens relative to red)

or do you think that those spikes are just a different redistribution of total red output and they do nothing to increase the total amount of red light the diode puts out but it just concentrates the total power in red in specific nms thereby not creating any difference between a standard 3000K or 4000K in broad wavelength distribution?
 

Rocket Soul

Well-Known Member
thanks for the charts and info. yes this scaling with spectral charts confuses me terribly. now i checked both numbers and yes they do look identical i wish they posted a wavelength distribution chart as you have posted.

so you are saying from quality point of view you’d personally consider going with 2700K with added uv and 660.

there is also 3000K on the chart i posted (the red line) do you think those spikes could help shift wavelength distribution to more orange red thereby increasing the intensity of red light compared to a standard 3000K? (hence also lowering the intensity of greens relative to red)

or do you think that those spikes are just a different redistribution of total red output and they do nothing to increase the total amount of red light the diode puts out but it just concentrates the total power in red in specific nms thereby not creating any difference between a standard 3000K or 4000K in broad wavelength distribution?
Sorry but its hard for me to say without pulling a risky guess out of my pants. My instinct says that the spikey spectrum is probably the same amount of reds, if anything it would probably be less than a standard 90cri spectrum but i think were splitting hairs. The spikey spectrum seems to have a bit more green, the main driver for high lums/lux.

Yeah, id probably go for something like the 3k spikey of those spectrums you posted for flower if your leaving it at white only. The less blue the trickier it is to tweak the environment for higher transpiration. 2700k may not be for every grow space. All i can say is try it and post the grow
 

crimsonecho

Well-Known Member
Sorry but its hard for me to say without pulling a risky guess out of my pants. My instinct says that the spikey spectrum is probably the same amount of reds, if anything it would probably be less than a standard 90cri spectrum but i think were splitting hairs. The spikey spectrum seems to have a bit more green, the main driver for high lums/lux.

Yeah, id probably go for something like the 3k spikey of those spectrums you posted for flower if your leaving it at white only. The less blue the trickier it is to tweak the environment for higher transpiration. 2700k may not be for every grow space. All i can say is try it and post the grow
before with my old fixture i was using a mix of 3000-4000-6000Ks but i was vegging under them as well. now this one mainly will be for flowering so maybe going with standart 3000K 90cris i have and some of these xlamp pro 9 (spikey ones) 3000K in a mix might be just a better way to go for it to try these ones out.

i’m not particularly against adding monos just adds more drivers and more cables but it would be nice to have some 660s and some fr-ir with uvas.

ok thanks for your input man appreciate it. i’ll keep it posted if a do go with the diy project. its just that i missed cobs. smd bars are good but cob bars performed equally well if not better especially when i wasnt limited by height which i will not be in a room setup.
 

Rocket Soul

Well-Known Member
before with my old fixture i was using a mix of 3000-4000-6000Ks but i was vegging under them as well. now this one mainly will be for flowering so maybe going with standart 3000K 90cris i have and some of these xlamp pro 9 (spikey ones) 3000K in a mix might be just a better way to go for it to try these ones out.

i’m not particularly against adding monos just adds more drivers and more cables but it would be nice to have some 660s and some fr-ir with uvas.

ok thanks for your input man appreciate it. i’ll keep it posted if a do go with the diy project. its just that i missed cobs. smd bars are good but cob bars performed equally well if not better especially when i wasnt limited by height which i will not be in a room setup.
By what metric or what judgement did the cobs perform better? Ive often wondered why cob users are so in love with them. We tried a few mixing with hps, seemed to generate light burns a fair bit. Also the whole heatsinking bit seems a lot more complicated. With strips and boards i just use alu sheet or similar, or even no sinking just boards. Whats the juice like that make you wanna keep squeezing? Cause it just seems like mostly downsides even though i realize there must be something there or people wouldnt stick with them
 

crimsonecho

Well-Known Member
By what metric or what judgement did the cobs perform better? Ive often wondered why cob users are so in love with them. We tried a few mixing with hps, seemed to generate light burns a fair bit. Also the whole heatsinking bit seems a lot more complicated. With strips and boards i just use alu sheet or similar, or even no sinking just boards. Whats the juice like that make you wanna keep squeezing? Cause it just seems like mostly downsides even though i realize there must be something there or people wouldnt stick with them
bars are good and i like the ones i have now but with cobs maybe its the concentrated light from a single source i got better lower growth. as far as the tops i dont see a difference between strips/bars vs cobs but with cobs i’d get better deeper growth. so basically longer colas. yeah keeping them high enough so they‘ll not burn can be a challenge. i had bleached buds under cobs when i was vertically restricted but with every setup i made using cobs i generally got more equal and deeper ripening and no drawbacks for me except the active cooling. i use thin and light heatsinks and mount pc fans.

the thing is if i train my plants to be just a single layer of main colas i’d probably wouldnt even notice this difference but i like to have longer colas. so i dont know man there is nothing tangible to show why i enjoy cobs but it just performed well for me in the past and the same fixture after 3yrs continous use is still performing well for my friend in his setup.
 

crimsonecho

Well-Known Member
By what metric or what judgement did the cobs perform better? Ive often wondered why cob users are so in love with them. We tried a few mixing with hps, seemed to generate light burns a fair bit. Also the whole heatsinking bit seems a lot more complicated. With strips and boards i just use alu sheet or similar, or even no sinking just boards. Whats the juice like that make you wanna keep squeezing? Cause it just seems like mostly downsides even though i realize there must be something there or people wouldnt stick with them
this was my old cob bar setup i basically want to take this 3x 1m bar setup to 3x 2m with double the diode count.
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