Natural light spectrum.. Why do we use these so much blue lights?

[djf91]

He clearly states he runs his lights all channels 100% then said when he runs just blue growth is slowed. That’s pretty obvious if you’re using half the power of the fixtures.

Nice that you’ve still ignored the peer reviewed study I shared that proves blue is what corals are most sensitive to.

No I don’t care for narratives. I’m just sharing facts. As I said, I don’t care if people run their tanks in full 100CRI or straight windex blue - everyone has their preferences and trying to tell someone e they’re doing it wrong because it’s not their taste is just silly. To put out false statements that blue is worse for corals because of how you comprehend someone’s context, when there are literal scientific studies that prove otherwise, is what pushing a narrative means.

Again, here’s the scientific study. Please share your thoughts on why it’s wrong.

Red Light Represses the Photophysiology of the Scleractinian Coral Stylophora pistillata - PMC

Light spectrum plays a key role in the biology of symbiotic corals, with blue light resulting in higher coral growth, zooxanthellae density, chlorophyll a content and photosynthesis rates as compared to red light. However, it is still unclear ...

www.ncbi.nlm.nih.gov

And here’s another one.

Effects of LED Light Illumination on the Growth, Digestive Enzymes, and Photoacclimation of Goniopora columna in Captivity - PMC

Coral aquaculture is a new industry, which is of great importance to the sustainable development of coral reefs and meeting commercial needs. Light sources are crucial for the growth of corals because zooxanthellae provide them with essential ...

www.ncbi.nlm.nih.gov

And there’s tons more I can keep sharing that prove it repeatedly.

I never said the blue spectrum was bad for corals, bud. I said only giving them blue light is not giving them everything they need.

 

[buruskeee]

I never said the blue spectrum was bad for corals, bud. I said only giving them blue light is not giving them everything they need.

Ummm….

“I tell people if you’re going to grow them only under blue light, they’re going to grow slower”.

“if I turned down all of the channels except for blue, then I would be giving them less light, and I would see slower growth”

And BTW, I’m not advocating for using only blue to light your tank. My whole point, in answering the OP’s title, is that the blue/violet part of spectrum is the most important part in terms of coral health/growth.

I personally use a slightly whiter AB+ spectrum because it’s what I like most visually.

 

[Anxur]

No word.. Only fact..

 

[VintageReefer]

You’d be surprised what 2 years of blue and violet only can do

I don’t want to hear that blues doesn’t give everything they need.

And this isnt some super fancy expensive fixture. It’s old school viparspectra’s running blue channel only for 2 years

 

[Lasse]

The first one is interesting because they in the middle of the discussion text just confirmed that the whole investigation could be irrelevant.

More specifically, the zinc concentration in the experimental system was 79.7 μg L−1, a concentration known to be in the toxic range for some coral species [24]. It is thus notable that narrow-bandwidth blue light seems favourable in a high-zinc environment, although it is unclear why. It is possible that blue light protects against zinc-induced reactive oxygen species [25], [26], [27] by enhancing the production of fluorescent proteins [7], pigments that possess antioxidant activity [12], [28] (also see below on reflection).​

IMO - the second article lost its value for me in the last sentence of the article

At present, the light exposure at the CITES-certified Taiwan Coral King coral farm (Kaohsiung, Taiwan) is at wavelengths of 400–470 nm. Moreover, to conserve energy, daily light exposure can be reduced to 6 h. Under these conditions, the annual output of G. columna colonies in 150 × 60 × 30 cm glass tank can reach 3000.

The corals in this test was all grown up below this light that they claim is the best. I does not says anything how it is in nature.

There is more - the spectrum of the white light is not reported. One cannot then know whether white light with the same intensity in the blue area as the experiments with only blue and purple gives higher growth or not. In addition, the white light used does not contain wavelengths that have been shown in tests to contribute to photosynthesis (below 440 nm) - my blue highlight

IMO - both this investigation only shows that it is possible to have corals to thrive and grow during monochrome blue, purple and orange light but not so good in monochrome green and red light if the corals are pre grown in an blue environment (400-470 nm)

This articles together with a couple more have lead to the misconception that red photons (wavelengths) are harmful to corals and their zooxanthellae. People think that because red is incorporated in full spectra light - you should not use that or not use red att all

All of this investigation only shows that corals do not thrive and grow below a monochromatic red light but are able to grow and thrive below monochromatic blue light. With monochromatic means only red or blue light.

In an earlier thread @oreo54 and @jda publish two interesting pictures. They are very informative regarding what is discussed in this thread. Excuse me both for using your posts in this thread. First the spectra in oceanic water from Oreo54's post

Note - this is from Oceanic water but many reefs are in costal waters and the light penetration is different in coastal water - red wavelengths goes deeper in coastal water - see this graph (from here)

And now Jda´s thought-provoking image (from here) I have seen similar landscape by myself in Thailand - at noon!

By the way @jda - in that thread you ask for safe UVA bulbs - have you tested "Black Light" bulbs - common in disco:s?

Sincerely Lasse

 

[Lasse]

I don’t want to hear that blues doesn’t give everything they need

But do you know the outcome if you have had full spectra light with the same PAR for the purple/blue part that you have now?

Sincerely Lasse

 

[Lasse]

However - IMO - high intensity of wavelengths below 470 nm can improve the colouration but it is the intensity of the blue wavelengths that is important - not if there is other wavelengths present or not. There is some indications that blue light can trigg the production of "sunscreen" pigment in corals. This pigments is often bright coloured. Its also possible that the florescence ability serve as a protector against intensive radiation - instead of take the energy from the incoming photon into the photosynthesis chain - it just return it with a lower wavelength (read other colour) and only gain some heat as a waste product. As you can see in @oreo54 :s graph the blue high energy radiation is highest near the surface!

​

Sincerely Lasse

 

[Anxur]

You’d be surprised what 2 years of blue and violet only can do

I don’t want to hear that blues doesn’t give everything they need.

And this isnt some super fancy expensive fixture. It’s old school viparspectra’s running blue channel only for 2 years

Seriously, everyone does what they want, but does this look like natural light to you?

 

[VintageReefer]

Seriously, everyone does what they want, but does this look like natural light to you?

Not my tank, but a friends

Did not say the ambience was supposed to be natural

I shared this tank as an example strictly regarding coral health - a combination of growth, and color - to show it is completely achievable with blue channels only

Could “better” results be achieved with more spectrum added? Who cares. Any one of us would love to have corals like this.

 

[VintageReefer]

And it’s obvious that if you run blue only on a light compared to an identical light you will get slower growth, because you have half the channels / watts.

In the example I posted above…the owner compensated and uses 4 fixtures instead of 2.

 

[Lasse]

And it’s obvious that if you run blue only on a light compared to an identical light you will get slower growth, because you have half the channels / watts.

In the example I posted above…the owner compensated and uses 4 fixtures instead of 2.

Whats happens if the owner slowly rise the white channel in these 4 fixtures?

Sincerely Lasse

 

[VintageReefer]

Whats happens if the owner slowly rise the white channel in these 4 fixtures?

Sincerely Lasse

As far as appearance?
Or as a growth experiment

 

[VintageReefer]

It is only a two channel fixture and I am not completely familiar with viparspectra but the white channel also contains red and other color, I am not sure the ratio. But raising white channel to 20% also increase red + others to 20%, albeit there is not an equal number of diodes

It is a similar fixture to reefbreeders photon v1, which I owned the 32 and 48” version of, and liked, but moved on to v2 for better individual channel control

 

[Lasse]

As far as appearance?
Or as a growth experiment

Both

increase red + others to 20%,

Yea - why not?

Sincerely Lasse

 

[djf91]

Ummm….




And BTW, I’m not advocating for using only blue to light your tank. My whole point, in answering the OP’s title, is that the blue/violet part of spectrum is the most important part in terms of coral health/growth.

I personally use a slightly whiter AB+ spectrum because it’s what I like most visually.

Um what? All my posts are saying the same thing. Anybody can see that.

 

[buruskeee]

Whats happens if the owner slowly rise the white channel in these 4 fixtures?

Sincerely Lasse

That's beyond the point. Obviously more PAR will get more growth. But we're talking PAR for PAR, lower part of spectrum grows more efficiently as the corals are most sensitive to those wavelengths. No one is saying coral won't use reds, greens, etc of the higher spectrum to grow.

The narrative of this thread is that "blue is a gimmick".

If you take 400PAR of only the sub 500nm spectrum vs 400PAR of 100CRI, what will grow better?

Or here's a better question - run only 550nm and higher at 400PAR vs sub 500nm. What will happen?

 

[buruskeee]

Um what? All my posts are saying the same thing. Anybody can see that.

Exactly, that you're implying that blue lights alone will slow the growth of corals, as I directly quoted those statements there.

 

[VintageReefer]

Whats happens if the owner slowly rise the white channel in these 4 fixtures?

Sincerely Lasse

You would increase par, and by increasing white spectrum you are also contributing to increasing blue and violet, used by corals.

His tank is already getting approx 800par at the surface, 350-450 mid level, and that’s pure blue par which isn’t the same as a full spectrum par

 

[Lasse]

Photosynthesis is quantum process - it is on or off at certain quanta of energy. The two main photosynthesis process are Photosystem I and photosystem II PSI and PS II. PS II comes first in the chain consist of light harvesting proteins (they are many) and need the energy quanta from a photon with around 680 nm wavelength

Its correct that lower wavelengths have higher energy quanta than higher wavelengths - its right that 420 nm has higher energy quanta compared with 680 nm but the first part of photosynthesis take place with the quanta of 680 nm in PSII reaction center. This means that the photons that is captured by light harvesting molecules (mainly Chlorophyll A. Chlorophyll C and carotenoids for zooxanthella's) of PSII will have its energy quanta slowly transformed down to the energy quanta of a 680 nm photon. This take place in different proteins organized like as a funnel in a chain that end with the energy quanta around 680 nm. The energy transport between these proteins take place with a process named resonance energy transfer. Its end at the reaction center of PSII with the energy quanta of one photon of 680 nm. This means that on photon captured at 425 nm will end up in the reaction center as an energy quanta corresponding to a photon with 680 nm wavelength. So each step in the chain down to the reaction center need 1 photon of what ever wavelength and whose energy quanta get closer to 680 nm with each step in the pigment chain. The energy lost in each protein step will end up as heat. To conclude 1 photon regardless of energy quanta (wavelength) ends up as a quanta equal with a 680 nm photon in the endpoint of the PSII. Shortly - one captured photon by the harvesting molecules end up with a energy quanta that is equal with a 680 nm photon. The process create chemical energy in the form of ATP

After this - an electron chain is created between PS II and PS I that in the end point convert the light energy of 700 nm into chemical energy in the form of NADPH

If you look at Corals most dominated light harvesting proteins - carotenoids (including β-Carotene, Diadinoxanthin and Peridinin ), chlorophyll A and chlorophyll C you will see their adsorption graphs below

There is some very interesting things in this graph, Peridinin that is one of the most common light harvesting protein among many stony corals has its peak around 510 nm - green may not be so bad as said before. Its important to stress that it can be different proteins in different coral and also there is different clades among zooxanthella in the same species of coral

About the colouration of corals I found this review https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2023.1204843/full. All interested of corals colouration should read this article - it clear up a lot. To read the chapter 3.2 was very educating and 4.2 was both confirming my old thoughts about fleshy deep water corals and refreshing.

I will state that I´m not a scientist and all that I wrote above is how I see it everyone is invited to correct me if I´m wrong

Sincerely Lasse

 

[Doctorgori]

Edit:
@Lasse thank you, as usual you do some digging and as also as usual come up with valid useful data ….

Some of my less educated thoughts:

I suppose you could just feed humans “Soylent green” and house them in a pure oxygen bubble tent and then supposedly create a perfect specimen but humans evolved to eat a varied diet and live in earths atmosphere
…,and Likewise corals evolved in sunlight, and not in some artificially tweaked slice of blue spectrum, and that’s regardless of whatever study supposedly proves otherwise (I question the thing about red light suppression of anything, I also call malarkey on red light “causing” algae growth)
anyway
the color temperature of the sun is
about 5900 K.

The Sun closely approximates a black-body radiator. The effective temperature, defined by the total radiative power per square unit, is 5772 K. The color temperature of sunlight above the atmosphere is about 5900 K. The Sun may appear red, orange, yellow, or white from Earth, depending on its position in the sky.