# build my led spectrum help



## indignation42 (Mar 26, 2014)

Hello, first post here.
I have been reading and learning a lot thanks to everybody here.
It seems that everybody loves the Finnex and build my led lights.

I purchased a Finnex planted+ for my first tank (29 gal. bowfront) thanks to good reviews from everyone here. seems like the light is working very well.

It is now time for me to purchase a light for my new 125 Gal. tank.
Seems to me that my best option for medium light on a tank this size is a build my led light. At least for the money that is.
On that note i have been trying to read around and see what nm light that plants use the most and a way to also give a good visible light spectrum at the same time. Over at the GE (General Electric) web site, they say that 612nm (if memory serves) and 660nm in the red spectrum are the most used by plants as well as 470nm in the blue. They also suggest that ultra violet light plays a role in helping plants utilize light better. It also sounds as though the red spectrum being a higher frequency produces more photons and therefore needs less light to accomplish the same thing as blue light since blue is lower frequency and therefore less photons.
So i included two 470nm blue and one each 615nm and 660nm red and one 405nm IR led and the rest 6500k. this seems to give me a 10232 CCT, and 130.94 micromoles/sec.
micromoles
micromoles
micromoles

All this being said I played around with their do it yourself spectrum calculator and came up with what seems to me a good spectrum but i have no experience in these matters so i thought that i would post here and see what you smart people thought of this.

here is the link to my spectrum. 
http://www.bmlcustom.com/custom-report-details/?partNo=PS7290S101AAMAARAJATAAMAA

Thanks for any help. 
:smile:


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## aquabruce (May 10, 2012)

Welcome to TPT.

I don't know enough about building a DIY spectrum to answer your questions but there are a few large tanks with BML lights on this thread that might help you find what you're looking for http://www.plantedtank.net/forums/showthread.php?t=481026&highlight=buildmyled+club


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## jeffkrol (Jun 5, 2013)

indignation42 said:


> Hello, first post here.
> I have been reading and learning a lot thanks to everybody here.
> It seems that everybody loves the Finnex and build my led lights.
> 
> ...


One of the GE references:









My take (nothing wrong w/ yours) on lighting.. This one is optimized to a high CRI w/ high PAR..
The PAR could be higher w/ substituting 6500k for 3500k... but I feel that 3500 k are sort of special being high in other red (600ish).. more so than 6500k.. It is a variation of BMY 5000k lighting.. I've not included royal blue in this one. I do like it in a multi-channel build but I have a hard time justifying in a 1 channel one ..
http://forum.buildmyled.com/index.php?threads/new-5000k-planted-tank-spectrum.225/


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## indignation42 (Mar 26, 2014)

thanks for the reply. 
Is the inclusion of the 470nm blue an issue for algae growth or something that i am not familiar with?


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## jeffkrol (Jun 5, 2013)

indignation42 said:


> thanks for the reply.
> Is the inclusion of the 470nm blue an issue for algae growth or something that i am not familiar with?


Not really though reefers think red causes algae and fw-ers think blue causes algae.. go figure..

Most "horticultural" LED's use deep red plus blue in a large red dominant ratio i.e say 1B to 9DR to maximise PAR and minimise waste energy so to speak.. which of course looks "ugly"..well unless you like purple..
http://www.molecularplantgrowth.com/philips-greenpower-led-production-module/#.UzL6TIWa-09
Optimized lighting


> Two spectrum versions are presently available. Next
> to the most commonly used deep red/blue mix we
> offer a deep red/white version if work light is needed.


https://store-ut7xea.mybigcommerce.com/content/Production module-Brochure-US.pdf

So you need to balance "look" w/ PAR.. ......... 
So in my opinion using "blue" in a 1 channel design is a bit problematic and somewhat unnecessary if you add white. White LED's are blue /w phosphors so you do have blue regardless..UNLESS you like blue looking tanks.. or you have soo much plant mass that you don't notice it.
In a multichannel LED you can "play" more.. 
Technically RB,DR, and Cyan = white.. just a fancier version of RGB......... 

Spectrum of a 6500k LED.....you have plenty of "blue"........... though not royal blue.. as much









Absortion spectra for pigments:









currently I favor cyan (IF REALLY Cyan, they have been manuf. hybrid LED's which are just green/blue combos) to use for green and hopefully hit the caretinoid absorption band..and spread out the "blue" wavelengths.......
Good CYAN (500 nm depending on bin.. and in the "hole" of white LED's)









Bad CYAN:








Royal Blue for fun.....









Your 470nm blue works fine and is very close to the cyan.... just pushes the CRI lower and into the blue range.. where I prefer a "neutral" or warmer tank........


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## indignation42 (Mar 26, 2014)

Thank you for your input.
I think I have made up my mind and used your suggestion to use cyan as the 6500k's do have a lot of blue already. 

http://www.bmlcustom.com/custom-report-details/?partNo=PS7290S101ATAOATAAATAOATA

Seems to give good red, blue and still have a good CRI.


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## Steve001 (Feb 26, 2011)

indignation42 said:


> Hello, first post here.
> I have been reading and learning a lot thanks to everybody here.
> It seems that everybody loves the Finnex and build my led lights.
> 
> ...


Cyan should be included. I think this is a better spectral distribution
http://www.bmlcustom.com/custom-report-details/?partNo=PS1290S101ABOMOOPDHHFHETH

Here's another useful app. With this app you can see specifically the spectral distribution of each led's range. you can see too all leds are very much the same in this regard, so what you chose there can be input into the BML diy app.
http://www.plantedtank.net/forums/showthread.php?t=581729&highlight=


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## jeffkrol (Jun 5, 2013)

Steve001 said:


> Cyan should be included. I think this is a better spectral distribution
> http://www.bmlcustom.com/custom-report-details/?partNo=PS1290S101ABOMOOPDHHFHETH
> http://www.plantedtank.net/forums/showthread.php?t=581729&highlight=


THAT is like the "most perfect" CRI..
but to be honest.. I like mine above better ..


Less complicated.. slightly higher PAR more red but I do like your mix of whites. 
Again, personally, I would never use a green..


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## johnson18 (Apr 29, 2011)

If you haven't yet, once you kind of have an idea what spectrum you want, give BML a call and run it by them. Through my recent dealings with them, I found them to be quite knowledgeable and very helpful.


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## jeffkrol (Jun 5, 2013)

johnson18 said:


> If you haven't yet, once you kind of have an idea what spectrum you want, give BML a call and run it by them. Through my recent dealings with them, I found them to be quite knowledgeable and very helpful.


good advice..
Oh for fun I "built" another one shooting for high CRI..w/ as much red as possible..


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## jrman83 (Nov 22, 2010)

I like custom ideas and all, but do you really think that your plants will grow much better with something you design over some of the standard spectrums they have readily available?

I personally try to keep things as simple as possible when it comes to lighting. When it comes down to it I go by what I like when I look at the tank, keeping it within the spectrums that grow plants, and in keeping it just that simple it makes decisions that much easier. Even if your plants were to grow an inth faster than, say mine, don't think I would mind too much. 

Just seems like a lot of effort for some inferred difference that you may have with plant growth, but when you look at the tank you could possibly be totally dissatisfied. I would concentrate on things that make you happy visually, keeping it within the confines that you know plants are happy.

I have a dual BML over my 125g with one at 10000k and one at 7000k and love it. Could there be some other custom spectrum that would _look_ better? Hard to really say until you get it on your tank and see how your plants and fish look with what you have chosen.

Just my opinion.


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## Steve001 (Feb 26, 2011)

jeffkrol said:


> THAT is like the "most perfect" CRI..
> but to be honest.. I like mine above better ..
> 
> 
> ...


The reason to include green is to make the tank have high apparent brightness do to human vision having a peak response at 555nm. See
? You won't see the green


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## jeffkrol (Jun 5, 2013)

jrman83 said:


> I have a dual BML over my 125g with one at 10000k and one at 7000k and love it. Could there be some other custom spectrum that would _look_ better? Hard to really say until you get it on your tank and see how your plants and fish look with what you have chosen.
> 
> Just my opinion.



Well for starters it is fun. also gives one a fingerprint on it and.. to point out the obvious.. apparently one stock color is NOT enough.. 



> I have a dual BML over my 125g with one at 10000k and one at 7000k


Personally I do these for my own creations... not to buy from BML..
BML is one of the few companies that didn't just take "reefer lighting" and tweak it to "look better".. and then market it as FW.. so most "off the shelf" lights are not very thought out..so using their calculator and such is my small way of paying them back for being a good company..somewhat twisted logic I admit.. 

And as to BML they themselves do the same thing which is how they come up w/ their products..

It takes a leap of faith to design your own.. and not just grab off the rack. Certainly it is not for everybody..

For my first spectrum post above I just took their 5000k and Tweaked it for my own reasons.. 
Made is "slightly" less photosynthetically active but increased CRI by 2 points.
Neither of which is numerically significant..

Why did I bother? .. Because I could.. and I wanted to target the carotinoid absorption band better and add "green" for color...in this case "blue-green"
But you are right.. it certainly is not necessary.....


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## jeffkrol (Jun 5, 2013)

Steve001 said:


> The reason to include green is to make the tank have high apparent brightness do to human vision having a peak response at 555nm. See
> ? You won't see the green


I understand your use of it..

fun w/ it's compliment.....
http://www.biotele.com/magenta.html


> All the colours in the lightht spectrum have complements that exist within the spectrum – except green. There seems to be some kind of imbalance. What is going on? Is green somehow being discriminated against?


Guess I'm just discriminating against it..pick a shade..









Oh I forgot about this though it has nothing to do w/ perception:


> After a discussion with Build My LED co-owner Nick Klase, I was advised to add neutral white LEDs to the blue ones, as these would be a more efficient source of green light (and the spectrum of this fixture is subjectively very pleasing). In the LED industry, the low quantum efficiency of green LEDs is known as the 'Green Gap'. Blue and Red LEDs are very efficient, but scientists have yet to produce green LEDs that exhibit similar radiometric efficiencies.


http://www.advancedaquarist.com/2013/3/review


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## indignation42 (Mar 26, 2014)

How would this play out do you guys think?
Better cri, better cct and more ppf.

http://www.bmlcustom.com/custom-report-details/?partNo=PS7290S101AOATAAOMFAATAOA


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## jeffkrol (Jun 5, 2013)

indignation42 said:


> How would this play out do you guys think?
> Better cri, better cct and more ppf.
> 
> http://www.bmlcustom.com/custom-report-details/?partNo=PS7290S101AOATAAOMFAATAOA



i still have a hard time w/ using one "color" LED every 12" (I know really about 6") and getting universal coverage..


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## Steve001 (Feb 26, 2011)

indignation42 said:


> How would this play out do you guys think?
> Better cri, better cct and more ppf.
> 
> http://www.bmlcustom.com/custom-report-details/?partNo=PS7290S101AOATAAOMFAATAOA


The predominant color is blue. Does a bluish colored planted suite you?
Try for a K temp in the 5500K <6000K range. That is the K temperature of tropical and temperate sunlight.


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## indignation42 (Mar 26, 2014)

Am I missing something about this "blue"?
With a CRI of 98 doesn't that suggest that the colors would be correct?

Sorry if this is a silly question, I am very new at this but i do want to get the light right.


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