Citizen Horticultural COB CLU04H - Plant RB

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bles

Well-Known Member
Hi,
I managed to buy 6 of these COBs. Citizen horticultural LED. Plant RB version 200w. which is supposed to be best for plants. There is also a plant white version which suppose to be used above workstations for people to have better comfort and ease of plant diagnosis. Anyone has any experience with them?

Ive built a simple 300w lamp. 100 cm radiator and cobs mounted below. Arctic Cooling fan for active cooling and some sheet aluminium to cover the radiator and make air go through the whole length. Its driven by mean well hlg 320 1750b with potentiometer to dim it. So far it performs great. Light is typical blurple but with just a hint of white to it. Definetly white cobs are better to look at. Dont know the performance yet, im going to build second lamp and flower something with two of those for a total of 600w over 4x4.



 
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bles

Well-Known Member
Studying spectra output graphs of these and other COBs got me thinking. The lumen efficacy of a cob is not what we should be looking at. Since it represents the efficiency of a light source in a "lumen" range of spectrum. If we can agree that Lumen range is not ideal at driving photosynthesis this should tell us something. Higher CRI cobs and horticultural cobs have very low LER, but that does not mean they are less efficient. Their quantum output could be way higher because their peaks of spectral output reside outside of lumen range. When i was trying to decide which cobs to choose, i saw that lower CRI cobs had better LER and i started thinking why would i buy high CRI if its less efficient. Infact its not less efficient, its way more efficient at what we are trying to accomplish because it delivers more photons in other areas of spectrum where the chlorophyl can absorb and make use of most of them, Since i do not own any equipment its just my thinking on the subject and i would love to hear if someone have different opinion and is my thinking straight or not.
 
CobKits

CobKits

Well-Known Member
its just coincidental that cobs with higher CRI are better for our use, a consequence of phosphor and blue peak vs red 'hum' ratio.. overall plants dont care for CRI, they do plenty well under both HPS in the 20s and CMH in the 90s
 
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bles

Well-Known Member
Yes I agree they don't care about CRI. I should have been more precise. 99% graphs I studied were citizen clu series. So in this case higher CRI means red peak is shifted away from lumen area (around 600-610 in lower cri) to the longer waves which are better for chlorophyll (642-662).

In hps case I think we have tons of radiation in the red spectrum which gives us results. So low CRI is not important. But hps completely lacks the 430-453 peaks chlorophyll also uses. In fact even more. That is why I think mh and cmh bulbs are also giving results despite the lower lumen output.

The advertising of bulbs was completely off using lumens. Now its using PAR which is slightly better but still doesnt say what is most important. How much radiation is emitted in 430-453 and 642-662.
 
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CobKits

CobKits

Well-Known Member
i think its going to be impossible to have a level playing field as different plants also have different requirements. not until the curtain is pulled back and companies are all in marketing canna-specific lights will there be a "standard" and even then it will be hotly debated
 
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bles

Well-Known Member
My supplier just received 16 clu05h 400w cobs. I don't even know what to use to drive them hlg 480 each :)
 
Randomblame

Randomblame

Well-Known Member
bles said:
Yes I agree they don't care about CRI. I should have been more precise. 99% graphs I studied were citizen clu series. So in this case higher CRI means red peak is shifted away from lumen area (around 600-610 in lower cri) to the longer waves which are better for chlorophyll (642-662).

In hps case I think we have tons of radiation in the red spectrum which gives us results. So low CRI is not important. But hps completely lacks the 430-453 peaks chlorophyll also uses. In fact even more. That is why I think mh and cmh bulbs are also giving results despite the lower lumen output.

The advertising of bulbs was completely off using lumens. Now its using PAR which is slightly better but still doesnt say what is most important. How much radiation is emitted in 430-453 and 642-662.
Click to expand...

That's only half of the story...
Red and blue light are mostly absorbed at the outer perifery. Plants also needs a lot of green light which is used in the deeped sections..
I would mix them up with a few 4k or 5k 1818 or 1825's to add it, maybe in a 50:50 ratio...

@PSUAGRO have a 1750k Vero light in test, also 300w range. Maybe interesting for you to see..
https://www.rollitup.org/t/testing-timbers-b-lux-decor-vero-fixture-1750k-hello-beautiful-spd-finger-still-on-the-trigger.935965/unread
 
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B

bles

Well-Known Member
Randomblame said:
That's only half of the story...
Red and blue light are mostly absorbed at the outer perifery. Plants also needs a lot of green light which is used in the deeped sections..
I would mix them up with a few 4k or 5k 1818 or 1825's to add it, maybe in a 50:50 ratio...

@PSUAGRO have a 1750k Vero light in test, also 300w range. Maybe interesting for you to see..
https://www.rollitup.org/t/testing-timbers-b-lux-decor-vero-fixture-1750k-hello-beautiful-spd-finger-still-on-the-trigger.935965/unread
Click to expand...
Thank You for this info. Can You point me where to look for more info about green and other parts of color spectrum being used by cannabis plants?
 
Hybridway

Hybridway

Well-Known Member
CobKits said:
i think its going to be impossible to have a level playing field as different plants also have different requirements. not until the curtain is pulled back and companies are all in marketing canna-specific lights will there be a "standard" and even then it will be hotly debated
Click to expand...
Lol! Tell me about it.
 
Randomblame

Randomblame

Well-Known Member
bles said:
Thank You for this info. Can You point me where to look for more info about green and other parts of color spectrum being used by cannabis plants?
Click to expand...
I do not collect the pfd's, but a quick Google search brings some interesting research results

https://www.google.com/search?client=tablet-android-samsung&site=webhp&ei=lJkJWYaCJ4XCgAbT5prIAw&q=contribution+of+green+light+pfd&oq=contribution+of+green+light+pfd&gs_l=mobile-gws-serp.3...2230.2230.0.2571.1.1.0.0.0.0.0.0..0.0....0...1c.1.64.mobile-gws-serp..1.0.0.xFU2Jm6biTY
 
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