SPECTRA Website - Spectrum Approximation Tool

[Nano sapiens]

With Dana on the Lighting Forum, I've seen more spectrum talk lately and the realization by many that a truly accurate spectrometer is not cheap! Here is a nifty little program that might help those looking to create and/or validate their current LED arrays (especially handy for DIY'ers).

A while back when I was putting together my DIY LED array, I was looking for a way to verify spectrum and intensity without an expensive spectrometer. This SPECTRA website was quite helpful in validating that my initial selection and intensity of the LEDs was close (I used the content from Dmitry & Vahe's excellent Advanced Aquarist article to come up with the proper spectra and intensities: http://www.advancedaquarist.com/2012/10/aafeature). One must know (or have access to) the specs for the individual types of LEDs used (and number, of course) and then intensity for the types of LEDs can be manipulated to optimally hit the photosynthesis peaks, as well as sufficient stimulation of the fluorescent and chromo proteins. The program will tell you how close you are to 'optimal' (aka 'SCORE 100'):

http://spectra.1023world.net/

My original array's data input produced 'SCORE 97%'. A small increase in the deep red (via red 670nm LEDs) then brought it to 'SCORE 100':

The program will even show you how your spectrum compares to light at various depths in the ocean:

I've been running with this for ~1 - 1/2 years now with just some minor adjustments...and the corals seen to like it just fine.

While I can't vouch for the accuracy (need a good spectrometer to compare), I can say that my initial research into the type of light required (which determined the particular LEDs to use, the intensities required and the expected graphical representation), matched quite well with the program's graphical output. Based on this, it appears to me that the program's individual LED spectrum data was compiled from accurate spectrometer readings. Picking nits, what the program can't account for, however, is the wavelength binning differences of the individual diodes. But for getting 'in the ballpark', it's pretty good IMO.


Ralph -

 

[mcarroll]

What score does it give to a generic 2:1 blue:cool white LED array?

 

[Nano sapiens]

What score does it give to a generic 2:1 blue:cool white LED array?

You'll need to input the LED specifics into the progam to find out

 

[kevensquint]

How much would you pay for a decent spectrometer? Dana recommended I try the Pasco when the light passport was over my means. I am happy with it. That said it's not exactly cheap.
Here's a plot of an XM 10k over a Radium with it. The accuracy is +/- 3nm from 380nm to 950nm so it will cover the newly popular infrared. You can zoom in to see exactly what wavelength is causing a peak and overlay lights to compare. I asked them to widen the color background to cover the actual resolution because it gives the false impression that it reads a narrower spectrum.

 

[Dana Riddle]

How much would you pay for a decent spectrometer? Dana recommended I try the Pasco when the light passport was over my means. I am happy with it. That said it's not exactly cheap.
Here's a plot of an XM 10k over a Radium with it. The accuracy is +/- 3nm from 380nm to 950nm so it will cover the newly popular infrared. I asked them to widen the color background to cover that, because it gives the false impression that it reads a narrower spectrum.

There you are Jason! Good to see you here.

 

[Dana Riddle]

With Dana on the Lighting Forum, I've seen more spectrum talk lately and the realization by many that a truly accurate spectrometer is not cheap! Here is a nifty little program that might help those looking to create and/or validate their current LED arrays (especially handy for DIY'ers).

A while back when I was putting together my DIY LED array, I was looking for a way to verify spectrum and intensity without an expensive spectrometer. This SPECTRA website was quite helpful in validating that my initial selection and intensity of the LEDs was close (I used the content from Dmitry & Vahe's excellent Advanced Aquarist article to come up with the proper spectra and intensities: http://www.advancedaquarist.com/2012/10/aafeature). One must know (or have access to) the specs for the individual types of LEDs used (and number, of course) and then intensity for the types of LEDs can be manipulated to optimally hit the photosynthesis peaks, as well as sufficient stimulation of the fluorescent and chromo proteins. The program will tell you how close you are to 'optimal' (aka 'SCORE 100'):

http://spectra.1023world.net/

My original array's data input produced 'SCORE 97%'. A small increase in the deep red (via red 670nm LEDs) then brought it to 'SCORE 100':

The program will even show you how your spectrum compares to light at various depths in the ocean:

I've been running with this for ~1 - 1/2 years now with just some minor adjustments...and the corals seen to like it just fine.

While I can't vouch for the accuracy (need a good spectrometer to compare), I can say that my initial research into the type of light required (which determined the particular LEDs to use, the intensities required and the expected graphical representation), matched quite well with the program's graphical output. Based on this, it appears to me that the program's individual LED spectrum data was compiled from accurate spectrometer readings. Picking nits, what the program can't account for, however, is the wavelength binning differences of the individual diodes. But for getting 'in the ballpark', it's pretty good IMO.


Ralph -

Very interesting. I'll use this program and compare to my spectrometer and PAM fluorometer results. The only issue I have with estimations of spectral suitability based strictly on light quality is the effects of protective xanthophylls - it could be slight, or maybe severe. The PAM can determine non-photochemical quenching (effects of protective pigments) - We found the standard blue/white LED combination was least effective in promoting coral growth of the several lighting sources tested (this took months.) The PAM can determine effects in a matter of minutes. Then the question is if short-term results can be properly viewed as applicable to long-term results. Still, this program is pretty cool. Thanks for sharing!

 

[mcarroll]

You'll need to input the LED specifics into the progam to find out

I'm not that interested anymore* since my tank and lights have already been up up a long time. But I always wonder about stuff like that where someone fabricates an ideal such as in that tool, or if they update the tool at all.

B+W works great, so I was mostly curious since you tweaked your lights to 100% if you got anything more interesting out of the tool than I did back then? (Which, BTW, I do think it's cool for noodling around and it's a very cool tool in it's own right. I just wonder about the necessity or benefit, if any.)

* See old post here, and the posts before and after: Lighting spectra, Photosynthesis, and You

 

[Nano sapiens]

Very interesting. I'll use this program and compare to my spectrometer and PAM fluorometer results. The only issue I have with estimations of spectral suitability based strictly on light quality is the effects of protective xanthophylls - it could be slight, or maybe severe. The PAM can determine non-photochemical quenching (effects of protective pigments) - We found the standard blue/white LED combination was least effective in promoting coral growth of the several lighting sources tested (this took months.) The PAM can determine effects in a matter of minutes. Then the question is if short-term results can be properly viewed as applicable to long-term results. Still, this program is pretty cool. Thanks for sharing!

Great Dana, thank you. I'd be very interested to see your comparative results.

As I reviewed the second graph showing my LED array's spectral output and the overlaying of various depths in the ocean, I can't help but notice that my hyperviolet and royal blue spectum peaks are similar to what would be encountered at 1 m of depth, the true violet peak (~403 nm) is more similar to 20 m depth and the red spectrum is most similar to ~5 m depth. I've been running this spectrum/intensity for 1 - 1/2 years with good color and growth so I know it works, but can it be improved upon?

Since corals are known to regulate their zooxanthellae population based on spectrum queues that indicate to the coral how deep they are, I can't help but wonder if some of the problems we see with STN/RTN might be exacerbated by us supplying the corals with mixed signals as to 'how deep they should think they are', based on certain key light spectra. The question I'll pose is would an LED array spectrum that more closely mimics the UV/near UV up to blue and also red spectra intensity ratios found at a chosen depth in the ocean result in better long-term coral health?

Ralph -

 

[Nano sapiens]

I'm not that interested anymore* since my tank and lights have already been up up a long time. But I always wonder about stuff like that where someone fabricates an ideal such as in that tool, or if they update the tool at all.

B+W works great, so I was mostly curious since you tweaked your lights to 100% if you got anything more interesting out of the tool than I did back then? (Which, BTW, I do think it's cool for noodling around and it's a very cool tool in it's own right. I just wonder about the necessity or benefit, if any.)

* See old post here, and the posts before and after: Lighting spectra, Photosynthesis, and You

I can say that the results from this current LED array have been excellent. Compared to an older, less sophisticated DIY LED array, the stony coral pigmentation, especially, improved greatly and growth shot up ~40%. Some of this was due to slightly higher intensity and better light spread, but I believe that having a more complete and optimized spectrum was a strong contributing factor.

 

[Dana Riddle]

Great Dana, thank you. I'd be very interested to see your comparative results.

As I reviewed the second graph showing my LED array's spectral output and the overlaying of various depths in the ocean, I can't help but notice that my hyperviolet and royal blue spectum peaks are similar to what would be encountered at 1 m of depth, the true violet peak (~403 nm) is more similar to 20 m depth and the red spectrum is most similar to ~5 m depth. I've been running this spectrum/intensity for 1 - 1/2 years with good color and growth so I know it works, but can it be improved upon?

Since corals are known to regulate their zooxanthellae population based on spectrum queues that indicate to the coral how deep they are, I can't help but wonder if some of the problems we see with STN/RTN might be exacerbated by us supplying the corals with mixed signals as to 'how deep they should think they are', based on certain key light spectra. The question I'll pose is would an LED array spectrum that more closely mimics the UV/near UV up to blue and also red spectra intensity ratios found at a chosen depth in the ocean result in better long-term coral health?

Ralph -

Many questions. Tim (Wijgerde) and Kinzie (as well as myself) have published works describing red wavelengths as potentially harmful (although red light seems to promote photosynthesis better than blue wavelengths, and also seems to regulate chlorophyll/zoox density. This regulation seems to be the protective measure against too much red light, as would be seen in the shallows.) Blue light, on the other hand, doesn't seem to promote photosynthesis as well as red (but light weighted towards the blue end promotes at least some colorful, protective chromoproteins and fluorescent proteins.) Looking forward to lighting experiments judging the effects of wavelength. As far a proper ratios of blue to red, most corals (as everyone knows) are found in environments where blue-green wavelengths are dominant and I used to recommend this mix of light and spent a lot of time on it. After too many replies of 'I didn't like the look' or 'My wife made me change the lights because it made the carpet look purple' I gave up on recommending the 'best' light. Still, I find it fascinating and will share the results of future experiments with those truly interested. Pardon my rambling...

 

[Nano sapiens]

Many questions. Tim (Wijgerde) and Kinzie (as well as myself) have published works describing red wavelengths as potentially harmful (although red light seems to promote photosynthesis better than blue wavelengths, and also seems to regulate chlorophyll/zoox density. This regulation seems to be the protective measure against too much red light, as would be seen in the shallows.) Blue light, on the other hand, doesn't seem to promote photosynthesis as well as red (but light weighted towards the blue end promotes at least some colorful, protective chromoproteins and fluorescent proteins.) Looking forward to lighting experiments judging the effects of wavelength. As far a proper ratios of blue to red, most corals (as everyone knows) are found in environments where blue-green wavelengths are dominant and I used to recommend this mix of light and spent a lot of time on it. After too many replies of 'I didn't like the look' or 'My wife made me change the lights because it made the carpet look purple' I gave up on recommending the 'best' light. Still, I find it fascinating and will share the results of future experiments with those truly interested. Pardon my rambling...

Please feel free to 'ramble' as much as you like since it'll help those of us who have a keen interest in how corals utilize light.

I have read a number of articles suggesting that red light is a queue to corals that they are in shallower water as red wavelengths typically don't penetrate more than ~10 - 15 m. I have also read on a particlar lighting manufacturer's website:

Finally we have 395nm True UV, which not only adds to coral flourescence, but development of protective color pigments by again tricking the coral into thinking it's in shallower water

However, since UV has been found to penetrate rather deeply, I regard this comment with a raised eyebrow and I don't have any collaborating scientific evidence that this is true.

One of the most interesting articles I've run across is the one comparing LED and Plasma effects on various species of coral.

http://www.advancedaquarist.com/2013/2/aafeature

Of great interest to me was in how the two spectra differ and the different effects noted with the coral species tested. Creating an LED array to more closely mimic the Plasma spectrum might be an interesting endeavor.

The amazing adaptability of these corals to not just survive, but thrive, with such different lighting spectra is nothing short of amazing!

Ralph -

 

[mcarroll]

We found the standard blue/white LED combination was least effective in promoting coral growth of the several lighting sources tested (this took months.)

I presume this is not the same as saying B+W were ineffective in any way, but only that growth was slower? Or am I misinterpreting?

I run a very-low-power B+B+W setup and a "fuller spectrum" setup on two separate displays connected to the same system so have been doing some direct comparisons. I don't have a ton of corals in the test (no budget – donations accepted ) but there's very little difference in my experience so far. (Around 5 years for the current B+W setup. Radium halides before that. About 3 years for the "mainstream" fixture).

 

[Dana Riddle]

I need to re-examine the blue/white issue and suspect it is the role of protective xanthophylls doing their job. The PAM fluorometer can distinguish between photochemical fluorescence quenching (photosynthesis) and non-photochemical quenching and can tell me where the absorbed photons (now electrons) are going. Examining this wasn't in the scope of the growth project. So.... here we go again.

 

[mcarroll]

Answers always lead to more questions, don't they?!

(BTW, "fuller spectrum" means...no greens, no reds, no "UV"....it's a 160w Razor. On a simple lux meter it's more than 3x the intensity than the B+B+W.)