Lighting spectra, Photosynthesis, and You

  1. jedimasterben

    jedimasterben Bubble coral sting good

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    Lighting spectra, Photosynthesis, and You

    Hello all. Some of you may recognize me from Nano-reef and my posts about LEDs, DIY recommendations, etc. Figured I'd post this up over here, as well. Putting it in general hardware and lighting because it applies to more than just LEDs. :)

    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.

    Here is 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

    In it, there is a pretty staggering amount of in-depth information to read through. I’m going to sum it up and kinda generalize the best I can, so here goes!



    Corals contain a colorful symbiotic dinoflagellate called zooxanthellae that performs photosynthesis, providing the coral with energy (but does not fill the corals needs 100%, only energy, 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 c, peridinin, and neo-peridinin (notice no chlorophyll b, which is not present in zooxanthellae like it is in terrestrial and freshwater plants).

    These are the bulk 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.


    [​IMG]


    [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 blue-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 always present alongside chlorophyll.


    As you can see by the wavelengths provided above, violet and blue light makes up 100% of the carotenoid absorption maximas, but in chlorophyll, violet is the most important spectra, and red spectra is nearly as important as blue spectra. The bulk of photosynthesis comes from chlorophyll, so I’d think twice about not including red spectra in your lighting. This can be somewhat proven using good old metal halides – people always say “use 10K for growth, 20K for colorâ€, which makes sense, as a 10K bulb will have more red spectra than a 20K, which will emit nearly all of its energy in the 420-460nm range.


    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 recommend to use neutral white (4-5000K) and royal blue, with full-spectrum fixtures bringing in deep red (660nm), cool blue (465-475nm), cyan (495-520nm), and true violet (400-430nm, so no UV).


    After picking through this article, I'm convinced that royal blue is not nearly as critical to the growth of corals as we imagine, and put into our fixtures. 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 true 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 than Cree XT-E that peak at 455nm. The violet LEDs I would use are split half and half - Steve's LEDs sells SemiLED chips that are 410-420nm, with the peak at 417nm - right on target! In addition, LEDgroupBuy has a new custom bin of violet (not sure what Milad is going to call it yet) that will be available for sale within one week, it registers its peak at 430nm, which hits the OTHER big peaks in violet!





    I still recommend having neutral white and royal blue in a 1:2 ratio, but I think adding more cool blue and more violet is very 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! Since true violet LEDs hit such peaks within photosynthetic spectra, the PAR value they put out is great, 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. I have firsthand experience with this, for the first several months of my tank I could not keep SPS corals, they would all bleach out within a week or two of putting them in the tank from what I now know was too much light, but as soon as I started turning my violet LEDs down, I was able to keep them. Then again, I was using 16x true violet at 700ma over a 55g. A bit overkill in comparison to the eight I would recommend to use now. :D



    Hope that helps to shed a little light on the subject (pun intended ;) ). If you have any questions or need any clarification, or advice on what LEDs you should use, let me know, and if you have anything you'd like to add, go for it. :)

     
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  2. revsgirl

    revsgirl Well-Known Member R2R Supporter R2R Excellence Award

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    Great info! Thanks!
     
  3. revhtree

    revhtree Owner Administrator Staff Member Team R2R R2R Supporter R2R Excellence Award Photo of the Month Award Article Contributor Partner Member

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    Great article/thread! Stickied!
     
  4. jedimasterben

    jedimasterben Bubble coral sting good

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    Wow, the last thing I was expecting! Thanks! :)


    I'll be sure to keep the thread updated with new information, I'm already working on additions now. :)
     
  5. montethemoster

    montethemoster Well-Known Member

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    The combination of "educational information" and commercial links to specific led suppliers seems inappropriate to me. At the very least why not just mention the led brand and not specifically where to purchase them? To me this equals an advertisement and shouldn't be stickied. Even if the information provided is accurate it makes it less valuable to me because it falls into the infomercial category.
     
  6. jedimasterben

    jedimasterben Bubble coral sting good

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    The only reason I even mention the stores is that they are the only places that list the information given. LEDGroupBuy's 430nm LED is of private manufacture, and Steve's is the only place that stocks SemiLED 417nm and 445nm Rebel ES, as both stores get these bins specifically. If you can find any other location to list the same chips with the same wavelengths and bins, please notify me.
     
  7. cdrewferd

    cdrewferd Well-Known Member

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    Very good read. I for one appreciate you letting us know where to get a few of the more specific Bins. It's so hard to decypher all that stuff from the different websites.
     
  8. rajkovich207

    rajkovich207 Well-Known Member

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    Ok hopefully this is the right thread and someone could "shed some light" on this question. I currently am running 24 total LEDs over my 29g biocube. I have 14 royal blues, 8 10k whites, and 2 UV (I am unsure if they are UV or the true violet ones you are talking about). I keep reading how important it is to add the color LEDs so I was wondering if I should pull a couple of the whites and royal blues and swap them out for a red or cyan or even green, and by the sound of this article maybe even a couple of the warm whites. What are your opinions on swapping out some of the LEDs? as well as what colors would you go with and what LEDs would you replace? I am running bridgelux LEDs with maxwellen(7-12) drivers. I have been told that they can not be dimmed but I came across an ardiuno controller off of LEDgroupebuy.com called DIM4 that is supposed to be able to controll the drivers and also allows the addition of 12 more LEDS with out the need of another driver. IF I am able to confirm that this will controll the LEDS I planned on getting it in the next month or 2, and planned on using the aditional LED spots for the fuge, but would it be better if I used them for the tank instead?
     
  9. jedimasterben

    jedimasterben Bubble coral sting good

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    PM'd so as to not clog the thread.
     
  10. mainereefer

    mainereefer Well-Known Member R2R Supporter

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    I just asked about color spectrum the other day. I was told by a led light maker,corals use 450-455 other colors are for looks to the eye your chart shows color spiking at 435

    here is the link
    https://www.reef2reef.com/forums/led-lighting-specific/99597-why-not.html

    could you take a look and tell me what you think? your chart isnt like his chart and your info looks more like I was saying and being told it didnt matter "it was looks that I was wondering about
     
  11. jedimasterben

    jedimasterben Bubble coral sting good

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    I took a look at what they said, and the thing that stuck out most to me is that they mention chlorophyll b, which is not present in zooxanthellae. And then mentioning that cool white LEDs cover the full spectrum without any additions. Hobbyists are moving away from cool white because we've noticed corals are less colorful under them, as it doesn't hit specific spectra hard enough (amber and cyan are the two biggest in that respect) without additional supplementation. For a while now, I have been pushing everyone to stop using cool white for that reason. Neutral white may not look so different on paper, but in person, the difference is substantial.
     
  12. mainereefer

    mainereefer Well-Known Member R2R Supporter

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    I used cold white led 15k in color are they a waste as far as color and growth?
     
  13. jedimasterben

    jedimasterben Bubble coral sting good

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    Growth-wise, they're fine, but I'd never recommend anyone use whites that are over 5000K.
     
  14. iiluisii

    iiluisii Well-Known Member MTRCMember

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    Why can you explain more on this

    Sent from my SAMSUNG-SGH-I747 using Tapatalk 2
     
  15. Steven R

    Steven R Well-Known Member R2R Excellence Award

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    Wouldnt you wash the tank with this I know almost all distributors use Led's that are over 5K with a combination of 5k thrown in there? What do you base this off of?
     
  16. mcarroll

    mcarroll Well-Known Member R2R Supporter R2R Excellence Award Partner Member

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    This thread seems like a good place for this - hopefully it's found useful.

    I think most people discussing LED's (like me) could use an elementary refresher on LED basics and I just found an excellent one in an unlikely (to me anyway) place in Olympus Microscopy. Check out their link.

    It's very complete, so it may not be 100% interesting to everybody. Probably the second half where they get into colors more is most germane to this thread.

    Once you get that digested, stop by the Wikipedia entry on visible light absorption by water and digest that. (For additional relevant detail, check here.)

    With a little understanding from both links, you should see a greater understanding of why blue light, centered around 420nm, is so important to our mostly (few exceptions) deeper water corals: Red is practically non-existent at depth, while a large portion of blue light energy still penetrates.

    Whether naturalistic lighting is more or less aesthetically pleasing than red-boosted (or other color) is another matter, but in almost all cases is definitately a matter of aesthetics vs necessity or "correctness".

    For example, if you're trying to recreate a surface reef (not typical for most of us) then non-blue wavelengths should be relatively more intense, roughly according to the curve shown in the Wikipedia link. (Seawater will be different than pure water in actuality.) OTOH, "20k" lighting is a reasonable facsimile of a deep water environment. (Many tanks currently testing so-called full-spectrum lighting look like they were colored with crayons to me...very unnatural, if maybe plesant to some tastes.)

    I'm not sure if anyone is asking what "the correct lighting" is, but if so I'd say that's either unanswerable or it totaly depends on the specific envirmonment and corals you plan to support.

    -Matt
     
    Last edited: Jan 11, 2013
  17. jedimasterben

    jedimasterben Bubble coral sting good

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    Frankly, your first link will only be read in its entirety by a handful of reefers, and probably not understood by them. A good link nonetheless. :)

    Full-spectrum LED arrays are about trying to mimic or exceed the coloration achieved by that of halides and T5. The fact (yes, fact) that far red spectrum is photosynthetically useful is a plus. Just because it isn't found in nature doesn't mean that there is no benefit to providing it in captivity. If we do not provide red spectrum, vast numbers of corals will be pretty bland in color, and the aquarium will simply look dull, muted and lifeless (and Sanjay Joshi agrees). Fluorescence is easy to achieve with LEDs - good coloration is not, and unfortunately not many reefers really know the difference between the two, and is why stores are selling the heck out of cheap chinese fixtures using ultra-cool white LEDs and royal blue only.
     
  18. mcarroll

    mcarroll Well-Known Member R2R Supporter R2R Excellence Award Partner Member

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    While I'm not taking bets, I don't tend to sell people this short on what they may or may not be interested in learning about, so we can all expect more of the same from me. ;-) Thanks for being frank! (Maybe we'll at least grow that handful a bit - I'd hope people trying to experiment in this area would find this stuff highly relevant!)

    Specifically: "Full-spectrum LED arrays are about trying to mimic or exceed the coloration..."

    Radium 20K lights have been the gold standard of reef lighting to me since forever. (YMMV) While Radiums do have a small 660nm spike in their light curve, none of the "crayola" full-spectrum tank pics I've seen look anything like Radium light. Ones that do look similar to Radium lighting don't look remarkably different than my 2B:1CW LED fixture, making be wonder why bother? I guess for you my only point would be that so-called "full spectrum" lighting - as I have seen on virtually every thread (here, elsewhere) I've visited on the subject - is about aesthetics. I won't attempt to argue the specifics of that (as above) because by its definition aesthetics are very subject to personal taste - and have little or nothing to do with coral growth or (so far as we are able to gauge it) health.

    Outside of some few, very technical reef-related articles (which are excellent) I have seen precious little of anyone here at the discussion level trying to gauge any health benefits to "color-boosted" LED systems. (That's my term.) By contrast I've seen many, many folks looking for "more pop". And there's nothing wrong necessarily with "tweaking the color of one's tank" of course - it's your money/your tank. :) To me just as important as tweaking color (maybe more) is to understand the fundamentals of what are going on with the light and water as this is what is driving the various light consumers (chlorophyl, pigments, et al) and their evolutionary adaptation.

    Trying to inject some bit of this understanding (what little I possess, anyway) into this discussion is my only goal. :) How can that hurt anyone trying to experiment with adding color to their LED system?



    Maybe dress my point of view another way...less technical...
    (or feel free to skip down to the P.S. if you just like technical! ;))

    After all the reading, it seems that "the full spectrum crowd" is telling me that my blue-heavy, washed out (to them) 20K-ish tank is somehow "missing something" and not only that, but "Sanjay Joshi agrees". :sad: Eek! Where's my Cyan LED?! LOL

    What I am saying back to the crowd, if you will, is that "no, that is incorrect."

    First, nature looks closer to "20K" where most of our corals are from - not like the "full spectrum" tank shots I've seen. Second, why would I (or you? or anyone?) ask Sanjay or anyeone else to say how my tank looks? It's aesthetics! (i.e. beauty is in the eye of the beholder.) ;) What I mean is that under relatively naturalistic light in my tank my corals are healthy as gauged by growth and look great to me. Isn't that the point?

    In fact, the "full spectrum" crowd (again, in virtually all cases that I've seen) is adding what's not naturally there and doing so in unnatural proportions when compared to any naturalistic light. Not that it's wrong to do so, but just that it is what it is. If you want "extra colors" then there's no better time than now, using LED's, to get em! But it's not particularly natural, and no need to pretend it is otherwise.

    Love to hear some more thoughts!

    -Matt

    P.S. Here's another very complete analysis of the subject (another not for faint of heart...but the graphs will be clear to most anyone) of light color and water if anyone has room to digest some more. :) It's one of the reef-related sources mentioned....and one that also confirms red as an aesthetic addition for coral color. (A very minor point in the overall article, of course.) One key quote for those who aren't gonna click and read: "...note that the 400-500nm range is the most required, since it provides the best coloration and fluorescence in corals; whereas, the longer wavelength radiation in 500-700nm range is poorly utilized by marine photosynthetic organisms."
     
  19. jedimasterben

    jedimasterben Bubble coral sting good

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    Well, if even one person finds that useful then you've done a good thing in posting it. :)

    Lack of coloration, specifically in red corals. Throw a bright red or orange acan under your lighting and you'll see them fade out. Under a Radium, that wouldn't happen because it has peaks in far red and cyan, which helps keep colors from that part of the spectrum to stay as they are (or even improve in coloration).

    [​IMG]

    To match the actual light that it appears to be to our eyes is difficult, at best, to mimic with LEDs. We can get close, but unfortunately that's it - only close, the technologies are too dissimilar to match.

    It's mostly aesthetic, yes - as are Radiums and ATI T5 bulbs, etc. If nobody cared about how their corals looked, we'd all be running 6500k lamps over them.

    Typically, people want the brightest coloration they can get from corals. That would mean that there is enough light for them photosynthetically to lower the amount of zooxanthellae they need, and sometimes in response to receiving more light in specific spectra, they will even produce more intense coloration as a natural protection against receiving too much light. This is the process I assume is happening when adding in deep red.

    Yes, there is little info about it - and mostly because the general consumer wants their tank to look blue and grow corals, and they don't understand what is going on or how any of it works, they want it that way and that's that. As the information is much more readily available on the internet now, a lot more people are learning what is actually going on.

    Wider-spectrum lighting is catching on a lot more (finally) and within the next year you'll be seeing more fixtures using warmer white chips in their fixtures to avoid the anemic color that some fixtures get (such as the AI Sol). Maxspect is one of few fixtures to do that and has some of the nicest coloration I've seen in a commercial unit (and without adding a dozen different colors of LEDs), and I look forward to seeing what they come up with in the future.

    And it is, indeed, missing something if you use narrow-band lighting, which is what LEDs are. There are certain colors that simply will not be in your tank if you use a lot of blue spectrum and high-kelvin white chips. It does not take a lot of additional spectrum to increase color rendition and you'll notice an immediate difference in the way the corals look.

    Not a single light source we have, besides plasma lighting, can or will ever mimic what the sun is capable of. If I take a coral that is red and I put it in my tank, I want it to be a red coral, which takes red light to accomplish. I don't want my tank to look anything like what you'll see vendors taking pictures of (and if anyone does, God help 'em!), but I want my corals to be healthy, bright, and colorful, in that order, and to get that it takes more than 400-500nm light to accomplish. (I'm actually going to be doing an experiment soon in a small spare tank I have using only light in that spectra using true violet [405nm], hyper violet [430nm], Rebel ES RB [445nm], Cree XT-E RB [452nm], cool blue [475nm], and cyan [495nm], with 'pink' [450nm & 520-630nm wide-spectrum] and deep red [665nm] on standby).

    I have been through that article many times, it is very informative, and reading through the comments (especially when calling out Ecotech for saying they use 442nm chips from Cree, which don't exist) Vahe and Dmitry tell it like it is. :)
     
  20. mcarroll

    mcarroll Well-Known Member R2R Supporter R2R Excellence Award Partner Member

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    The brightest coloration, judging from examples posted online, is freaky looking - too purple, too red or colored by crayons - and obviously not very natural. I wouldn't describe 20K halide or my 2B:1CW LED's that way.

    While Radiums (or 20K lighting in general) took lighting more toward "natural" (and I don't think anyone from pre-20K days would argue it) then I would argue the trend we're talking about which started in T5's and has translated to LED is going "away from natural". Do we care about that? Maybe, maybe not (personally, yes)....but from the photo-evidence it's true.

    No, incorrect to say it's missing something unless you can define what perspective you're coming from. Compared with nature, it's missing very little to nothing. Arguably some sub-450nm light, but which - if any - and how much are very much open to debate. Of course I'll concede if we're just talking about personal opinion on favorite colors to bring out....but I'm really comparing to nature to the extent possible. I don't know what other "standard" there is. (And opinion is fine as long as you know what you like and like what you have!)

    Actually some discharge lights have come really close to the spectrum of sunlight....is plasma more than vaporware? Anywho...I don't think anyone in the hobby has been heavily involved with emulating daylight since the Iwasaki+03 days. The reason? Most corals we keep these days are not corals from surface waters. Those using actual daylight (solatubes, greenhouse, skylights) are the only real exception I can think of. Should be interesting to the "full spectrumers" to see the results those people get. (Both the good and bad, of course.)

    And as mentioned, if you take a red coral, it probably doesn't look red in nature. Adding red light is OK as the camouflage probably isn't needed in captivity anyway, but steps away from the natural setting and ignores the reason for the the red coloration in the first place. :)

    -Matt

    P.S. Thanks for the continuing discussion! This is great, and the one of the main reasons I like hanging out here! :)
     

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