3500k vs 4000k vs 5000k ?

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PurpleBuz

Well-Known Member
The Green Griffin said:
I understand, PB! My choice of wording could be better. I'm comfortable saying "most" rather than "nearly all", but I'm also not saying that the theoretical discussions are bad. I've followed your posts for a while and I know you are seeking to gain as much knowledge as possible and share what you learn. My comments were in no way meant to disparage anyone. Could not mention all the people doing great disciplined work in this forum and adding to the knowledge base, the list is waaaay too long. Regardless of how knowledgeable and experienced someone might be, speculation is still theory, extrapolating from known facts to postulate what could be a new truth. But it is important to speculate, theorize and discuss because that's how we learn, share and plan our next testing. Without a doubt, the better your background and experience, the better and more valuable those theories will be. Even the 'unproven' (quantitatively speaking) tribal knowledge derived from experienced growers is important to steer future testing, because we have a lot of very smart people here who love and know this funny plant well and their instincts are probably correct in many (if not most) situations.

Keep sharing, brother!
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wow dude you sure are chatty! I get what your saying.
 
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PurpleBuz

Well-Known Member
mauricem00 said:
watt for watt you get more lumens but what about usable light? the lumen depreciation I cited came from charts published by cree and bridgelux. my 200 watt vero 18 fixture looked brighter than my T5s but GPW was no different. 45% green light for the cobs VS 20% green light for the T5 mix I use. I can get 4 replacement sets for my tubes for less than the cost of one replacement set for my Cobs. I am just relating my personal experience with the strain I grow in my environment and growing conditions and for me T5s still seem like the best option. I'm not saying they are the best option for everyone. hope we can keep this debate friendly
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- well the vero18s I use don't have anywhere near 45% green.
- T5HOs should be changed about every 12 months continuous usage.
- Vero18s maybe once every few years if your running them at a reasonable current (<=1050ma) and can keep them under 50C.
- 30% increase in efficiency, try measuring it.
 
JorgeGonzales

JorgeGonzales

Well-Known Member
alesh said:
Almost exactly same numbers I had come with.
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Thank you. This is most interesting response in here (to me). Facts, not opinion, and good news for everybody.

It appears that by 4000K, 80CRI is throwing more photon energy than 90, but that doesn't matter much for growing plants. Maybe less relative green in the higher CRI phosphor recipe is a more efficient conversion. That's pure stoner speculation.
 
mauricem00

mauricem00

Well-Known Member
PurpleBuz said:
- well the vero18s I use don't have anywhere near 45% green.
- T5HOs should be changed about every 12 months continuous usage.
- Vero18s maybe once every few years if your running them at a reasonable current (<=1050ma) and can keep them under 50C.
- 30% increase in efficiency, try measuring it.
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have you actually done a side by side comparison grow? cheap chinese made T5 may not last as long but good quality commercial and german made P&A bulbs are much higher quality. some have an L89 life expectancy of 35,000 hours. in my side by side comparison grow with the same strain. all plants were vegged under T5s but half were flowered under cobs and half were flowered under T5s. my cobs were run at 600ma for maximum effiecentcy and I saw no difference in quality or yield. as I said earlier. I grow in soil not on chalk boards and I listen to my plants. not college professors :lol:
 
tstick

tstick

Well-Known Member
The gems of information in threads like this vary from reader-to-reader. Nikola Tesla could enjoy some of the posts and other posts could be enjoyed by Jethro Clampet. It's all good....just depends on what you're looking for. Personally, I don't miss a post by Sativied.

The truth in all of these pages of text and graphs and comparative charts is that everyone one of the lights/spectrums in question is capable of producing high-quality marijuana -if- used by a good grower and -if- good genetic stock is used. This is all just talk for the sake of talking....which is okay since this is a discussion forum. ;)

The least of the problems faced by growers is what the CRI number is or if the K is 500 warmer or cooler. Good growers, who have grown some of the dankest, most ridiculous weed that's ever been smoked, did so decades ago -long before there were any LEDs at all. Nitpickers gonna nitpick....:)

...but just to add another wrinkle to this master-debate....What say you all to the way that using some lenses can change the K? Back when I was going to order an Optic Vero light, I was instructed to order the 4000K due to the fact that the lenses would change the temp to something closer to a 3500K....If it IS true that a lens changes the color temperature, then which lenses are more drastic in this sense? -Those big, glass ones?
 
alesh

alesh

Well-Known Member
guod said:
www.sylvania.com/en-us/tools-and-resources/Pages/led-color-calculator.aspx
View attachment 3698544
your Excel sheet as CVS import under User Spectra - 1.column is nm.....
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I see. I can't say that I understand how the CCT calculations work...might be an error in my formulas. Good thing is that the tool shows all the variables - should be easier to find what I'm doing wrong.

But what I find odd are those µmol/(s-W) values. It's a simple calculation but I'm getting different results. Wondering why that would be...
 
guod

guod

Well-Known Member
1.there are different settings in the software

xiv. “Limit umol/s-W to 400-700nm”
Limits the calculation of the umol/s-W to the range of 400-700nm. If this is not checked then the
umol/s-W will be calculated over the range of 360-830nm or 360-1050nm if the “Include IR”
option is checked.

can be found in the Data - Menue

2. i don´t know how the calculated the Integral 1,2, ...nm steps.
also the software interpolates the imported Datapoints to smooth the curve.

CCT calculation depends on the used Model. a good overview can be find at Wikipedia.
https://en.wikipedia.org/wiki/Color_temperature...
scroll down to
Correlated color temperature
 
Yodaweed

Yodaweed

Well-Known Member
You guys speak about all these hypothetical situations but you never actually test your hypothesizes, it's basically just hearsay. The LED section on this forum is the blind leading the deaf.
 
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churchhaze

Well-Known Member
Yodaweed said:
You guys speak about all these hypothetical situations but you never actually test your hypothesizes, it's basically just hearsay. The LED section on this forum is the blind leading the deaf.
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You should go pick up a copy of Rev thenatural's... i mean... RM3's book if you want the truth.
 
SaltyNuts

SaltyNuts

Well-Known Member
I'll throw it out there that there is no definitive answer to what balance of spectrum works "best" because there are too many variables to quantify here, especially considering strains and phenotype, and preference. I'm ok with this being a Bro-science place, if that's what you want to call an informal forum where people share their findings and interests, outside the purview of a true science laboratory. Subjective and incomplete data is a given. Pics of gardens and equipment with a little background info are the interesting thing here, in my opinion. Anyone who comes on here like a know-it-all just sounds like an asshole. I'm sorry, that's human nature. Can I prove in a lab that you sound like an asshole? The flaming makes it hard to recognize the pearls of wisdom here and stay on topic. I'm not discounting anyone, though. Continue.
 
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