Lighting spectra, Photosynthesis, and You (new plots!)

[jedimasterben]

With full-spectrum LED arrays becoming all the rage nowadays for better coloration, more and more people are considering them, but I see people saying all the time "dude, but corals only use blue light for all their energy and red only helps algae grow, ur an idiot if you add red light" (direct quote from one user). This is just not so.


I found a paper called "Photosynthetic Pigments of Symbiotic Dinoflagellates (Zooxanthellae) from Corals and Clams" by S.W. Jeffrey and F.T. Haxo, 1968. You can find the PDF file here: http://www.biolbull.org/content/135/1/149.full.pdf

The paper contains a large amount of data - I will attempt to simplify it a bit and explain how it applies to our lighting.


Corals contain a colorful symbiotic dinoflagellate called zooxanthellae that performs photosynthesis, providing the coral with energy (but does not fill the corals needs 100%, all corals need to be fed, but that’s another post for another day). These contain pigments of certain colors that absorb light. The biggest players involved are chlorophyll a and chlorophyll c2, with the accessory pigments peridinin and neo-peridinin behind them.

The following are the majority of pigments contained in most zooxanthellae (listed in order of highest population), their spectral maximas (the peak absorption wavelengths), and the color they reflect back. The wavelengths are essentially the average of what is presented in the article, with the range usually ~4nm or so. They were taken from many specimens, including Tridacna gigas, Tridacna crocea, Hippopus hippopus, Pocillopora sp., Amphidinium sp., and Peridinium cinctum.



[now, you might be wondering 'if these pigments are so colorful, why is it that when corals are starved of light and build up zooxanthellae numbers, why do they turn brown instead of, say, green or red? Well, zooxanthellae typically contain two or more of these pigments - what do you get when you mix dark green and brick red? brown. ]


Chlorophyll a outnumbers chlorophyll c ten to one in zooxanthellae in corals, but in tridacnid clams, chlorophyll c is present at two-thirds chlorophyll a, making it much more prevalent. Peridinin and neo-peridinin constitute 77-84% of total carotenoids present and are considered true accessory pigments to chlorophyll, as they are almost always present alongside chlorophyll in a PCP complex.

Here are some spectral plots of these pigments:

Chlorophyll a


Chlorophyll c2


Peridinin (neo-peridinin is similar)


PCP, peridinin-chlorophyll-protein complex, made up of eight peridinin and two chlorophyll a molecules


Dinoxanthin (dia-dinoxanthin is very similar)


Beta carotene


As you can see by the wavelengths provided above, violet and blue light (and a splash of green) makes up 100% of the carotenoid absorption maximas, but in chlorophyll, violet is the most important spectra, and red spectra* has nearly as high a maxima as blue.



When it comes to LEDs, we can pick specific wavelengths we want to add. It started off with cool white (7-10,000K) and royal blue (445-455nm) (and some Chinese fixtures use cool blue instead of royal), and now we use neutral white (4-5000K) and royal blue, with full-spectrum fixtures bringing in deep red (660nm), cool blue (465-475nm), cyan/turquoise (495-520nm), and true violet (400-430nm, so no UV).


After picking through this article, I'm convinced that royal blue is, in fact, not as critical to the growth of corals as typically though. Violet, deep red, and cool blue are the most important, in that order. That being said, most royal blue LEDs will touch on the higher violet peak of chlorophyll a, but not as strongly as a hyper violet LED will. This is one reason I prefer using Luxeon Rebels for my royal blues, as their peak is at 445nm, so closer to hitting chlorophyll a's peak.

I still recommend having neutral white and royal blue in a 1:2 ratio (still waiting on manufacturers of LED fixtures to come to terms with this), but I think adding a bit more cool blue and much more violet (particularly the 430nm range) is beneficial.

A word of caution on both - too much cool blue can give a Windex-like look to your water, and too much violet can very easily bleach your corals, so keep them on their own dimmable drivers! Quality violet LEDs emit large amounts of light (up to 960mW at 700ma, which is nipping at the heels of royal blue XT-E and Rebel ES at about 1,050mW at 700ma), but since they are so close to being ultra-violet, our eyes simply cannot see most of the light they emit, so they appear dim, which makes it easy to add more and crank them up because it's like you can't tell they're even on.


Hope that helps to shed a little light on the subject (pun intended ). If you have any questions, comments, additions, or need any clarification, or advice on what LEDs you should use, let me know. Come check out the full-spectrum LED thread, as well! http://www.nano-reef.com/forums/index.php?showtopic=294733

*A note on red light: Dana Riddle has written several articles that include the 'damaging' effects of red light on corals and zooxanthellae, and I see it repeated all too often in regards to using deep red or even neutral/warm white LEDs. In the experiments done, a red LED was placed directly adjacent to the coral flesh and bleached it out. I firmly believe that this is NOT the proper way to determine if a coral can handle red light (which, so far, I haven't found one that cannot), and blasting a coral with an unregulated amount of light that may be hundreds of times more powerful that it was subjected to before will certainly bleach any coral, and it does not matter what color or wavelength the light is. I can just as easily bleach a coral with blue light as I can with red light - it all comes down to acclimation and control of the output, just like how we must acclimate corals to our lighting when we bring them home.

[uglybuckling]

It is a real game-changer that most zooxanthellae do not include chlorophyll B.

 

This is a great post and I think worthy of further testing.

 

I'll volunteer to try a warm white (and/or deep red), violet, and cool blue-based system for my frag tank in several months when I get around to setting it up, with maybe a few royal blues thrown in to hit some of the accessory pigment peaks (but certainly not in the 2:1 RB:NW ratios we use for display tanks).

[gulfsurfer101]

Great post, thanks for sharing!

[patback]

Jedi, you are always posting great info on LEDs and set ups and drivers. To the average hobbiest however, it is all Latin. If you could find the time, I think it will benefit EVERYONE and push some more people towards led if you could make an idiots guide to LEDs and drivers.

[gulfsurfer101]

I think that's already been covered there good buddy;)

[jedimasterben]

Jedi, you are always posting great info on LEDs and set ups and drivers. To the average hobbiest however, it is all Latin. If you could find the time, I think it will benefit EVERYONE and push some more people towards led if you could make an idiots guide to LEDs and drivers.

ugly's design thread covers most of it. I've been working on and off with a designer that would calculate what your LED strings voltage will run, how many drivers you need, etc. I'm also looking at writing a new 'Ultimate LED Guide' since evil hasn't updated his since April 2010. Updated information needed for Rebels and Cree alike, as well as adding Bridgelux to it (both the 'cheap' ones and the quality high-powered ones).

[boxboy]

Great Post Jedi Thanks for taking the time to share your research

Ive always took, valued and used your suggestions seroiusly!

The importance of using cool blue,violet,red,netural white,cyan and royal blues should not be under estmated

[Paleoreef103]

One thing I'd like to add is that we don't have really good LEDs for the 430nm range. Yes we have violets that are 400-430, but the peak is in the 415nm range with just the tails hitting 430nm (the 415 peak of true violets is close enough to the 410 to be acceptable). T5s are your best bet for strong 430 nm peaks (ATI True Actinic is a beast for this wavelength, but Blue+ and Purple + also have broad peaks in this area). Chlorophyll C is still important, just not as critical. The accessory carotenoids are still going to be secondary to Cholorophyll a and c. This also means you can get a small benefit from 630 nm "cree-red" especially for clams. I think this also shows that rebel Royal Blues actually work better than cree royal blues as Rebels run from 440-450 while crees run from 450-460. Great read, Jedi.

[jedimasterben]

One thing I'd like to add is that we don't have really good LEDs for the 430nm range. Yes we have violets that are 400-430, but the peak is in the 415nm range with just the tails hitting 430nm (the 415 peak of true violets is close enough to the 410 to be acceptable). T5s are your best bet for strong 430 nm peaks (ATI True Actinic is a beast for this wavelength, but Blue+ and Purple + also have broad peaks in this area). Chlorophyll C is still important, just not as critical. The accessory carotenoids are still going to be secondary to Cholorophyll a and c. This also means you can get a small benefit from 630 nm "cree-red" especially for clams. I think this also shows that rebel Royal Blues actually work better than cree royal blues as Rebels run from 440-450 while crees run from 450-460. Great read, Jedi.

The best violet LEDs are from Epistar (their 410/420nm "dual-core" chips) and from SemiLED (410-430nm, with a peak at 417nm). The Bridgelux chips that most places sell have a peak at 405nm, but still touch on chlorophyll a's lower peak.

 

And I had assumed that what little chlorophyll c was available in corals, that taking care of peridinin/neo-peridinin should be more of a priority.

[Milad LEDGroupBuy.com]

One thing I'd like to add is that we don't have really good LEDs for the 430nm range. Yes we have violets that are 400-430, but the peak is in the 415nm range with just the tails hitting 430nm (the 415 peak of true violets is close enough to the 410 to be acceptable). T5s are your best bet for strong 430 nm peaks (ATI True Actinic is a beast for this wavelength, but Blue+ and Purple + also have broad peaks in this area). Chlorophyll C is still important, just not as critical. The accessory carotenoids are still going to be secondary to Cholorophyll a and c. This also means you can get a small benefit from 630 nm "cree-red" especially for clams. I think this also shows that rebel Royal Blues actually work better than cree royal blues as Rebels run from 440-450 while crees run from 450-460. Great read, Jedi.

 

We like to innovate

Under 7 days:

 

 

 

BTW i dont mean pre orders in under 7 days on those 430nm Exotic but actual being up for sale and shipping to your front door in under 7 days. 1 of 4 new things coming out from us before Christmas.

[jedimasterben]

We like to innovate

Under 7 days:

 

 

 

BTW i dont mean pre orders in under 7 days on those 430nm Exotic but actual being up for sale and shipping to your front door in under 7 days. 1 of 4 new things coming out from us before Christmas.

holy ####. my life kinda needs those.

[uglybuckling]

Dude, those are amazing. Good timing, Milad. Definitely counting those in for my grow tank "hit all of chlorophyll A and C and peridinin's spectral peaks" fixture.

[Milad LEDGroupBuy.com]

holy ####. my life kinda needs those.

 

Jedi you are going to spoil all the surprises with your posts. You already uncovered 2 of the 4 things we are bringing out for Christmas, stop posting!

 

BTW thats data from our actual spectrometer and not a spec sheet. So its the real deal.

[jedimasterben]

Jedi you are going to spoil all the surprises with your posts. You already uncovered 2 of the 4 things we are bringing out for Christmas, stop posting!

 

BTW thats data from our actual spectrometer and not a spec sheet. So its the real deal.

hot damn! just keeps getting better and better!

 

 

I wonder what I can post next.

[Paleoreef103]

Mother of god... Those 430s are crazy! I might have to get a six pack of them for my 40 breeder, but I don't want to order until I find out what those other 3 items are. Last time I missed out on OCWs, by about a week. Milad, excellent job on the 430s.

[jedimasterben]

milad, who is the manufacturer? i dont know of any with that spectral output.

[jen1363]

Wish I could have read this post about two weeks ago

[Milad LEDGroupBuy.com]

milad, who is the manufacturer? i dont know of any with that spectral output.

 

custom

[Paleoreef103]

custom

Out of curiosity, are these going to have the recommended 500 mA maximum for drive current like the TVs and the OCWs? Is one of the other surprises going to be a 500 mA max driver? Other guesses: Chlorophyll A 3 up (TV, 430 nm hyper blue, and deep red), a premade PAR-38/ nano fixture, and possibly a yellow LED (but I can't imagine a high demand).

[Milad LEDGroupBuy.com]

Out of curiosity, are these going to have the recommended 500 mA maximum for drive current like the TVs and the OCWs? Is one of the other surprises going to be a 500 mA max driver? Other guesses: Chlorophyll A 3 up (TV, 430 nm hyper blue, and deep red), a premade PAR-38/ nano fixture, and possibly a yellow LED (but I can't imagine a high demand).

 

Kinda guessed another one and a half.

[jedimasterben]

IT WASN'T ME THIS TIME!!

[uglybuckling]

Edit: post removed due to SPOILERS.

 

Out of curiosity, are these going to have the recommended 500 mA maximum for drive current like the TVs and the OCWs? Is one of the other surprises going to be a 500 mA max driver? Other guesses: Chlorophyll A 3 up (TV, 430 nm hyper blue, and deep red), a premade PAR-38/ nano fixture, and possibly a yellow LED (but I can't imagine a high demand).

 

I'd do it as 430nm hyper blue, deep red, and either cyan or cool blue to hit accessory pigments. 430nm is very close to true violet as-is. This way also stands a better chance (although I will admit, still not likely) at balancing the colors in such a way that they won't look totally wild and crazy. Maybe it'll be a 4up with DR, cyan, cool blue, and hyper blue.

 

I bet the 500mA driver is coming. I also bet I know the other two but (after writing them above) I felt bad about stealing thunder, so I've decided to not guess.

[uglybuckling]

Jedi, you are always posting great info on LEDs and set ups and drivers. To the average hobbiest however, it is all Latin. If you could find the time, I think it will benefit EVERYONE and push some more people towards led if you could make an idiots guide to LEDs and drivers.

 

ugly's design thread covers most of it.

 

I ordered parts today for a new light, for a 12x24 inch footprint tank, which will be using one of badfishreefsystems' AIO kits. I'm going to be building the light on-camera, and talking about every aspect of it as I go.

 

Reading fifty pages of this stuff (or writing it...) makes my head spin. It's very abstract stuff and I agree, pretty much Latin unless you've done it before. Text is a poor medium for communicating information about this sort of thing. I want to make this stuff more accessible, more intuitive, and more familiar to people trying to build their first fixture.

 

One thing I'd like to add is that we don't have really good LEDs for the 430nm range.

 

 

We like to innovate.

 

I'll be using the new 430nm emitters in the aforementioned fixture, and likely adding a few above my macro tank as well (in the Evil Cluster).

[HVani]

So what about those of us who are not very Handy. Is there a LED fixture on the market that seems to have this true full spectrum that corals need?

[jedimasterben]

So what about those of us who are not very Handy. Is there a LED fixture on the market that seems to have this true full spectrum that corals need?

Not really. Most all are still cool white and royal blue only. The few that do incorporate more LEDs only add cool blue, green, and red.