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jedimasterben
Bubble coral sting good
I know, and this thread has gotten away from its topic several times now lol. If you look at the data we have now, anything you choose is the correct one.
Lighting spectra, Photosynthesis, and You
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Gwitness
Well-Known Member
Haha I gotcha! And yeah this thread is great, but some of these comments have confused the crap out of me now!! one info says red light isn't bad and then someone sends a link about red being bad! Haha
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jedimasterben
Bubble coral sting good
If you read the link, lighting a tank with incredible intensity of solely 660nm light (to the order of 256µmol of PAR) is detrimental to the health of one strain of Stylophora pistillata - it doesn't say anything other than that, and neither does the peer-reviewed data published to PLOS ONE, which is what the article was supposed to summarize.
Gonzalez0324
Community Member
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.
[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.
Hope that helps to shed a little light on the subject (pun intended
hey i have a question. i have a 48x18x24 75g tank with 2 hydra 52. i don't know how to set up my lights in order to have that nice dark blue without compromising the health of my corals. i have some LPS and SPS. I was under the impression that the deep blue was the beneficial one for the corals, but as i read ur article and based in the info, the good "" blue is the royal blue and like you mentioned that gives it a windex sort of color in the tank. so do you have any advice as to what percentage is should have the royal blue, deep red, and violet (being that those are the 3 main colors right ?) I'm new to the hobby so any help with the appreciated. thanks
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jedimasterben
Bubble coral sting good
Like mentioned above, any setting you choose is the correct one. Growth happens across the entire visible light spectrum, with short wavelengths having the most photosynthetic activity.
KologneKoral
Community Member
Why so aggressive about this report. This supports what we have know for a long time, but no one was able to re-document and expand upon since Dana Riddle's original work. Yes, red light is potentially problematic for corals. As with any poison, the dosing makes the difference. And we seem to have an interesting mechanism at work.
There is no need to remove the red spectrum from our lighting, but it is simply not required by the corals, which we knew. It may help in certain pigment production and have an effect on metabolism, which is clearly confirmed by the study. When out of balance to other available wavelengths (specifically blue 450nm), it will kill the coral. We knew this, but hadn't defined the mechanism. Now we know it is a trigger created by the spectrum, which induces a change in the zooxanthellae populations. Too much red spectrum and the zooxanthellae cannot reproduce and die off, as well as the coral trying to reduce the amount of zooxanthellae to prevent further damage.
Clearly, the adaptation period we give our corals is key in allowing any given coral to deal with a new light spectrum. OK, nothing really new, but now much better defined and understood.
And, let's be real, although S. pistillata was the species used in this work, and then only a single clone, other studies used other species and had the same result. This is clearly a basic mechanism of corals and would seem to be particularly important for reef flat species. This ability of the coral to know where it is growing allows it to take best advantage of the situation. If not for this ability, then corals would be much more specialised and I doubt we would be able to maintain aquariums as we currently do. The corals would be much too spectrum specific. S. pistillata is found over a very wide range of depths.
Further studies acroos the spectrum would be interesting to see which corals and pigments respond to which wavelengths at at what intensity. Until now we have tended to overlight our corals and heavily in the blue spectrum, which promotes certain pigments and supports the human aesthetic. Clearly there is more to learn and manipulate in order to produce a variety of results. I would like to see some work dedicated to yellow pigments, which tend to be overwhlemed by GFPs in tanks, thus becoming a lime tone.
Still lots to learn.
Jamie
There is no need to remove the red spectrum from our lighting, but it is simply not required by the corals, which we knew. It may help in certain pigment production and have an effect on metabolism, which is clearly confirmed by the study. When out of balance to other available wavelengths (specifically blue 450nm), it will kill the coral. We knew this, but hadn't defined the mechanism. Now we know it is a trigger created by the spectrum, which induces a change in the zooxanthellae populations. Too much red spectrum and the zooxanthellae cannot reproduce and die off, as well as the coral trying to reduce the amount of zooxanthellae to prevent further damage.
Clearly, the adaptation period we give our corals is key in allowing any given coral to deal with a new light spectrum. OK, nothing really new, but now much better defined and understood.
And, let's be real, although S. pistillata was the species used in this work, and then only a single clone, other studies used other species and had the same result. This is clearly a basic mechanism of corals and would seem to be particularly important for reef flat species. This ability of the coral to know where it is growing allows it to take best advantage of the situation. If not for this ability, then corals would be much more specialised and I doubt we would be able to maintain aquariums as we currently do. The corals would be much too spectrum specific. S. pistillata is found over a very wide range of depths.
Further studies acroos the spectrum would be interesting to see which corals and pigments respond to which wavelengths at at what intensity. Until now we have tended to overlight our corals and heavily in the blue spectrum, which promotes certain pigments and supports the human aesthetic. Clearly there is more to learn and manipulate in order to produce a variety of results. I would like to see some work dedicated to yellow pigments, which tend to be overwhlemed by GFPs in tanks, thus becoming a lime tone.
Still lots to learn.
Jamie
TJ's Reef
Valuable Member
flowflezy, thanks for revising this thread again. Even though the way original research document above provided by Ben is fairly old the pertinent information is still quite valid. Part of what frustrates me to no end on these LED lighting topic threads is the constant regurgitation of miss information on the necessity of broad spectrum including Reds and Greens. The internet and Forums like R2R can be such great educational tools if one is already educated enough to distinguish good facts from bad opinions. Hopefully this thread will stay resurrected for the long haul
Cheers, Todd
Cheers, Todd
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SantaMonica
Valuable Member
For those interested in growing macros or building scrubbers, here is my favorite spectrum graph:
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jedimasterben
Bubble coral sting good
That's just a graph for chlorophyll a. There is a lot more to it than that. The best growth I've ever seen from a scrubber was from using four 660nm Rebels, four 445nm Rebel ES, four 430nm LEDgroupbuy hyper violet, and two 2700K Rebel ES.
jasmine.rave
New Member
Hi jadimasterben. Your point of view is very reasonable and professional, and I also agree that Maxspect is the best LED aquarium light in the current market. Do you think some bulb or linear work good on saltwater plant? Full spectrum is important, but do you think the ratio also matters?
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jedimasterben
Bubble coral sting good
Plants are a little different than corals. They contain chlorophylls a and b (not a and c like corals) and need quite a bit more red light for best results. If it is for an unseen refugium, mixing 660nm deep red, 450nm royal blue, and warm white LEDs in a ~4:1:1 ratio seems to give the best results for me. If it's a display refugium or a display tank, then you'll want it to be primarily warm white and royal blue, with only a few deep reds as it will overpower the other colors significantly.
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jedimasterben
Bubble coral sting good
Corals use chlorophyll for photosynthesis, which absorbs red light. If you have evidence to support that chlorophyll does not absorb red light, please present it.
I'll send you a PM, as this isn't much the thread for that.
mcarroll
10K Club member
Please Present It?
In general, corals live at depth and have adapted not to need red light. Not sure about your request. I merely commented that your posting about the different chlorophylls and corals' lack of "B" also suggested the same.
Chlorophyll
Technically the dinoflagellates use chlorophyll for photosynthesis - not the corals - and that's important because there's some sophisticated symbiosis in between the two that shouldn't be glossed over. Good link.
And while chlorophyll absorbs red light, corals have made lots of adaptations to deal with red light because it can be bad and harmful. I don't think you can really say that corals use red light for themselves in any way - and they seem to be able to make-do without it.
But we've long known that corals are adaptable to nearly whatever light we put over them....as long as there's sufficient intensity and time allowed for adaptation. If someone thinks that redder or greener or purpler corals look better than naturalistic colorations, then the corals can probably deal with that. I just don't want to confuse things by saying such an environment is "better" or "preferred" so far as the corals are concerned.
The Report
Though it wasn't the point of the report someone mentioned earlier, the report does indicate one thing corals "use" red light for: An indicator of high-irradiance - a signal for the coral to throw up the light-shields. I know you've suggested this as a theoretical pathway to getting some pigments expressed, but has this panned out in practice yet as far as anyone has documented? Any links specific to this?
-Matt
P.S. I updated my post #24 in this thread since the R2R blog is gone....taking my pics along with it. Pics are now posted here.
eagle
Active Member
Great post mcarroll. I have read these threads and just shake my head. Guess I've been too lazy to find the links to the articles I've read lol. Thank you for posting some links. There's an older advanced Aquarist I read a long time ago that showed a study of growth rates under 20,000k, 14,000k, 10,000k, and 6500k. 20,000k had the best growth. 14,000 and 6500 were close together. 10,000k was by far the worst. Then they broke it down in the amount of red light each color temp had. Of course 10,000k has the most. So I've always believed the red stunts growth. I'm no scientist but the studies done are pretty cut and dry. Red seems to be great for algae and dino's. I think some people just want their tank to look a certain way which is fine, but I think it's been shown in plenty of studies that you get slower growth to necrosis to death depending on how much red you have.
Sangheili
Well-Known Member
This is awesome. Great find Squamosa. Only wish it had Luxeon-M diodes in it (so I could more accurately recreate my ATI Powermodule).
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