Red Light - Good or Bad for Corals?

[Dana Riddle]

These are two papers from over 30 years ago examining spectral composition and coral photophysiology:

Kinzie, R.A., P.L. Jokiel and R. York, 1984. Effects of light of altered spectral composition on coral zooxanthellae associations and on zooxanthellae in vitro. Mar. Biol., 78:239-248.

Kinzie, R.A. and T. Hunter, 1987. Effect of light quality on photosynthesis of the reef coral Montipora verrucosa. Mar. Biol., 94: 95-109.

In a nutshell, red light was found to regulate zooxanthellate density/chlorophyll content. In extreme cases, large amounts of red light bleached corals.

I did similar work in corals and LEDs in 2001 and 2002. Again, red light *potentially* causes coral bleaching:
http://www.advancedaquarist.com/2003/11/aafeature
Later work showed red light can be harmful (Wijgerde):
http://www.advancedaquarist.com/blog/scientific-evidence-that-spectrum-matters-for-coral-growth
So, if you're ramping up red channels to show off the colors of your clownfishes, are you seeing any negative effects on corals?

 

[marktea]

Following! I rub mine below 20% out of fear of burning my coral and nuisance algae. Would love to know of I'm just crazy

 

[mcarroll]

Doesn't red light have a (special?) role in photosynthesis between PI and PII?

I've also read that red light is used by corals somehow to sense how close to the surface they are.

I can imagine that provoking any of those things could be deleterious, but I haven't had a chance to dig into any of them...

2¢

 

[Dana Riddle]

Doesn't red light have a (special?) role in photosynthesis between PI and PII?

I've also read that red light is used by corals somehow to sense how close to the surface they are.

I can imagine that provoking any of those things could be deleterious, but I haven't had a chance to dig into any of them...

2¢

Yes, Far Red relaxes pressure on Photosystem II by draining off electrons waiting to enter Photosystem I. I have to wonder about the lack of this effect in deeper waters. Perhaps this explains (at least partially) why some zooxanthellae clades can never adapt to higher light intensity (such as a 'F' clade found in Montipora capitata.) Can you provide a reference on corals sensing water depth due to spectral qualities? I have some references that state this in a round-about way. Or maybe my memory isn't serving me as it once did.

 

[Dana Riddle]

Following! I rub mine below 20% out of fear of burning my coral and nuisance algae. Would love to know of I'm just crazy

Another data point - thanks!

 

[jsker]

Very interested in this. Out of recommendations and experience, not scientific. I run my reds at %10 presently and I am wondering should I cut the red down to 5% due to algae issues over that last 18 months?

 

[Sallstrom]

At work we run a Heliospectra LX602-C over our large reef tank. We have a ongoing project together with that company and we're able to try out their LEDs. The model is for greenhouses and have 450nm, 660nm, 735nm and white 5700K diods. I don't have all the data now, but I think about 40-50% of the diods are 660nm. So there is a lot of red The fixture is 600 watt.
This LED lamp is hanging together with several metal halides (400 & 1000 watts) over the tank. The LED is running at 100% 7 hours a day.
I can measure PAR when I get back to work, both all lights and only the red channel.

Okey, to the point I like to try things so I put the lamp over a part of this tank almost two years ago now. We have really nice growth and colours under this lamp. Sure, it's not only light from this LED lamp but mostly.
So in this tank under the present conditions the corals doesn't seem to be harmed by a lot of red light.
I can get back with pictures and more data when I get back to work on Monday.

/ David

Edit
Here is a thread about the tank I'm referring to:
https://www.reef2reef.com/threads/10000l-coral-reef-at-the-maritime-museum-aquarium-sweden.329812/

 

[najer]

I am a Pacific Sun hybrid user so no white leds. I run the standard Bali program so there is red in there a bit!
Very interesting!

 

[saltyfilmfolks]

IMO , the difficulty in fearing reds in our lights is , we don't know how much red we're specifically giving them.
I.e.
If the manufacturer has formulated the native color (all colors at full in say a 14-16,000 blend typically ) to not have a a significant amount of red already based on the aforementioned research, I'd kinda assume it's not too much of a concern.

In practice I would assume the best thing to do if a spectrometer is not available is to set each color level with a par meter or lux/FC meter and draw out the special ratios of your preferred color settings.

This would insure your 500 par blend does not have a 100 par red component for example.

 

[Lasse]

I am a Pacific Sun hybrid user so no white leds. I run the standard Bali program so there is red in there a bit!
Very interesting!

Me too and I have run an own PAR tabell with all colours at 100 % for more than 4 hours/day. Have done that for the last 4 months

Sincerely Lasse

 

[Lasse]

At work we run a Heliospectra LX602-C over our large reef tank. We have a ongoing project together with that company and we're able to try out their LEDs. The model is for greenhouses and have 450nm, 660nm, 735nm and white 5700K diods. I don't have all the data now, but I think about 40-50% of the diods are 660nm. So there is a lot of red The fixture is 600 watt.
This LED lamp is hanging together with several metal halides (400 & 1000 watts) over the tank. The LED is running at 100% 7 hours a day.
I can measure PAR when I get back to work, both all lights and only the red channel.

Okey, to the point I like to try things so I put the lamp over a part of this tank almost two years ago now. We have really nice growth and colours under this lamp. Sure, it's not only light from this LED lamp but mostly.
So in this tank under the present conditions the corals doesn't seem to be harmed by a lot of red light.
I can get back with pictures and more data when I get back to work on Monday.

/ David

Edit
Here is a thread about the tank I'm referring to:
https://www.reef2reef.com/threads/10000l-coral-reef-at-the-maritime-museum-aquarium-sweden.329812/

Here is the spectra for each 30 cm deptht of that tank. Measurements it taken in the Coral Light Project

Surface

30 cm

60 cm

90 cm

120 cm

150 cm

And a graph showing % of UVA (350-400 nm), Blue (400-500 nm), green (500 - 600 nm), Red (600-700) and Far red (>700)

Sincerely Lasse

 

[saltyfilmfolks]

Here is the spectra for each 30 cm deptht of that tank. Measurements it taken in the Coral Light Project

Surface

30 cm

60 cm

90 cm

120 cm

150 cm

And a graph showing % of UVA (350-400 nm), Blue (400-500 nm), green (500 - 600 nm), Red (600-700) and Far red (>700)

Sincerely Lasse

That is cool Lasse.

In America we have a saying, "I'm totally geeking out !"

 

[Lasse]

And here is a picture showing the first 40 cm below the surface. The Heliospectra fixture is rather close to this part of the aquarium

I´m not so afraid of red wavelenghts.

You can see how the birsds nest looks like - before the got to my aquarium and start to be like balls

Sincerely Lasse

 

[Sallstrom]

We have another tank with other "results". We decided to start with corals in our bambo shark tank this spring. And we wanted to try LED only. So we started with 3 Heliospectra LX602-C over a part of the tank. I did the same as before and put the lamps on 100% about 7 hours a day. After 2 month I changed to lesser red since the corals didn't look to well and I couldn't find something wrong with the water(but found some AEFW ). So perhaps the corals in this tank got wrong parts red/blue.

Now the corals look better but perfect. The Heliospectra model doesn't have that much blue and white so the PAR is not that high.

So IMO it sound like the combination of wavelengths might effect the respons.

/ David

 

[kevensquint]

I feel there is truth to the red light issue. But I also wonder if the water chemistry has an impact on how corrosive or not other things end up being such as red light. For example, if the same intensity of red light on X coral frag in a high nutrient test tank were compared against the same colony frag under the same intensity red light in a low nutrient test tank. Would the low nutrient tank frag pale out faster? IMO, yes. If that is actually the case then the impact of red light will be variable depending on the chemistry of the aquarium in question.

 

[Sallstrom]

I feel there is truth to the red light issue. But I also wonder if the water chemistry has an impact on how corrosive or not other things end up being such as red light. For example, if the same intensity of red light on X coral frag in a high nutrient test tank were compared against the same colony frag under the same intensity red light in a low nutrient test tank. Would the low nutrient tank frag pale out faster? IMO, yes. If that is actually the case then the impact of red light will be variable depending on the chemistry of the aquarium in question.

I agree. And flow. And a lot of other parameters. So my example is just an example, that in this case the corals reacted a certain way. This things is hard to test without getting other parameters to interfere, you'll need a proper lab

/ David

 

[Dana Riddle]

There are a couple of issues here - our eyes are very poor at measuring chlorophyll content (meaning shades of brown and their related chlorophyll/peridinin) and it takes a specialized meter to do so. A coral can be bleached and we wouldn't know it without a chlorophyll measurement. Growth rate is another metric that is almost impossible to compare/quantify between (or within) systems. Flow, for instance, can have a profound effect on coral photosynthesis and, by extension, coral growth.We can say 'My corals are growing' - but compared to what? I'm not trying to discount anyone's successes! Very interested in continuing this dialog!

 

[Lasse]

@Dana Riddle

A basic question of a thing that I´m not fully clear of. The action spectra as described in your article. How is this constructed? Does it shows – in a relative scale - how many photons of each wavelengths that will be absorbed (in %) or does it show - in a relative scale how much of the incoming light will be absorbed in different wavelengths? I.E. has the amount of photons of different wavelengths in the incoming light any importances? I hope you understand what I am meaning.

Another question is – in the graphs you write “Coral/zooxanthellae absorption” does that mean that there can be other things that absorb the wavelengths than just zooxanthellae? I´m clear over that the first figure shows the absorption from isolated zooxanthellae’s but can your technique give a good estimation of the zooxanthellae’s absorbtion?


According to your thoughts - how much has the oxygen tension in the microhabitat around the coral and the production of free oxygen radicals caused by the photosynthesis to do with the success of using wavelengths with high photosynthesis yield? I.e. – do you think that in this concern – the flow around the microhabitat of the corals is of very high importance?

Sincerely Lasse

 

[mcarroll]

Yes, Far Red relaxes pressure on Photosystem II by draining off electrons waiting to enter Photosystem I. I have to wonder about the lack of this effect in deeper waters. Perhaps this explains (at least partially) why some zooxanthellae clades can never adapt to higher light intensity (such as a 'F' clade found in Montipora capitata.) Can you provide a reference on corals sensing water depth due to spectral qualities? I have some references that state this in a round-about way. Or maybe my memory isn't serving me as it once did.

That was it!

I'm gonna see if I can dig up that reference on depth sensing.

Something else:
I think red light can also combine with "waste" red light in the emerson effect to drive photosynthesis.

Not exactly a primary source, but I've learned a lot from this:
http://plantphys.info/plant_physiology/light.shtml
Which is from the Fall 2015 Course Schedule of a Bio 4xx/Plant Pysiology class.

Info about the Emerson Effect is near the bottom of the first link, but anyone from this thread will have a tought time skipping the rest of the info – it's packed with goodies about photosynthesis.

 

[mcarroll]

;Jawdrop

Stony paradise!

Thank you for the realistic photo – it's absolutely stunning!!!!!