Coral and Macro Algae Spectrum
 

I've been doing some research on mainly different types of macro algae (Green Algae, Brown Algae, and Red Algae) and what color pigments they have (Chlorophyll A, B and C, Fucoxanthin, Phycoerythrin, ETC.) and what spectrum of light those pigments absorb and reflect during photosynthesis.

Most of the color pigments that are present inside macro algae and I'm guessing corals too have 2 main spikes in the color spectrum that they absorb the most. One in the blue area (425 - 495 out of all the pigments I researched) and one in the red area (630 - 665 out of all the pigments I researched). Out of the 2 main spikes, the blue spike is the bigger one.

What would happen if you gave macros or corals only lights that had a spike in a certain spectrum, like only actinics for the big blue spike? The light it would get would be very useful for the macro or coral, and it would not be any less amount of light if you just changed (let's say) an Actinic/Daylight setup to Actinic/Actinic.

And on a side note... Do both the blue and red spikes in the color spectrum that they absorb make the macros/corals grow? Or is it just one of these and the other pigment has a different purpose.

Thanks guys!

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I groe my macro algea with just blue(445) and red (460) leds and they grow like crazy :) I want to do a lil experiment with corals but havent gottem that far...if you are wondering I use 2 blue and 2 red both 3 watts

This is similar to the debate over LED fixtures. LED lights are not full spectrum lights like metal halides and because of this there have been many discussions over the effectiveness of LED lighting for reef tanks and success with coral.

My Led fixture has blue & royal blue LEDs in addition to cool whites. Once all my parameters stabilized and I started dosing kalk the growth of my corals has been great.

I do not know what exactly would happen if I only used the blue spectrum lights, this might be more of a question for the lighting forum or advanced topics forum. I was under the impression that everything would live/grow with just the blue spectrums but I have not read much about lighting since I made my purchase back in november so I cannot remember all the details.

Interesting responses. I am mainly interested macroalgae, just for future responses.

Mikez, if by red you mean 660nm, what kelvin color does that LED combo give off? How far away are they from the lights? What kind of macroalgae are you growing? Do they have good color?

Oops hehe yes I mean 660nm. Not sure on what kelvin it would be ill try and post pictures tomorrow. They sit about 6 inches away from water. I grow red gracillaria. The color is great deep red on main stems and bright red on growing branches. Havent lost any yet :)

When you say 6 inches are you referring to how far your LEDs are from the water? How far are you macros from the LEDs? So the red is very noticable? If you had to guess, if you added 3 more blues for a 4:1 ratio would the red go away?

Thanks for the responses

My fuge is shallow so same 6 inches. Yes very red....i had at one point 2 white a blue and red...but didnt get growth like now....i dont really go for look....its only to grow algea....what are you tryn to accomplish? Maybe I can help you better if you tell me what is your goal...not a led expery but I do mess with them well enough to get results :)

I'm going for looks and a little growth, because I'm starting a macroalgae tank soon. So all you did did was add more LEDs and your growth slowed down? Did you change the red LED?

No I was saying that before I have 2 white and 1 blue and 1 red, but didnt get growth like im getting now with 2 red, and 2 blue. Ok so in your tank are you looking to grow coral or just macro algea?

Just macro.

Here is a very specific question that will help me greatly:
Since the pigments in red algae only have absorption spikes in the red and blue areas, can an algae like red gracilaria or botryocladia live and grow and have color under blue lights only?

Here are some pics...not all that great pics but to give u an idea

http://i1161.photobucket.com/albums/...1338420686.jpg

http://i1161.photobucket.com/albums/...1338420939.jpg

http://i1161.photobucket.com/albums/...1338421000.jpg

Its not so much as having blue or red lights...what you need is the proper wavelenght...if you want a whiter look you can try led with 5700-6000k or like they call them warm white...
Im still experimenting with different leds so dont have all the answers...yet ;)

When I said blue and red lights I meant 450-ish nm and 620-660nm, and sometimes a 6500k light may not give off the assumed spectrum. This is why I am looking at specific wavelengths.

Well you saying the spectrums....plants need 660 nm and 445nms proven time and time again

Oh fyi im saying 660 and 445 cuz thats what I use ;)

But here is the dilemma, if red macroalgae reflect red light why does it need 660nm which is in the red spectrum?

They absorb some red but they get more of blue...i got my new experiment :) thanks...ill make a new light fixture with nothing but blues and see what I get

Have you seen really healthy gracillaria...its dark red really dark

I guess thats because it absorbs very little red light!

Because it is deep dark red does not mean it is healthier. The saturation of the color has to do with the intensity of light. If fact it grows faster and lighter red under more light, but not too much light. If you did an experiment where you lowered the light in your Fug more and more over time you would see the "Red" gracilaria, spelled with one L, get darker and darker red until you were not providing it enough light and it would start to recede and then die.