Light spectrums for corals

ZoWhat · Mar 14, 2019

Did some deep reading on light spectrum and what's best for corals.

PLZ go easy on me bc I'm not very TECHY. Amateur understanding.

Here's what I learned:

* visible light for corals range from VIOLET (around 380nm'ish wavelength) to RED (700nm'ish wavelength)

* WHITE LIGHT is the entire spectrum 380nm to 700nm being dispersed at the same time. Never knew that.

* sweet spot for corals is mainly 420 to 460nm which is variations of blue wavelengths. Minor sweet spots are a little bit of green (500nms) and a little red (600-700nms)

QUESTION:
1) If you basically BLASTED your corals with 400nm to 470nm blue light, would that pretty much be sufficient for coral growth and health?

2) What's the use of WHITE light? Aren't you blasting corals with the entire spectrum with too much unneeded green, yellow, red at high levels?

Question #2 is my biggest question

.

Rybren · Mar 14, 2019

@Dana Riddle would be able to address your questions. He has some awesome articles in Advanced Aquarist.

b4tn · Mar 14, 2019

I am glad you posted this. I have a similar question to add to the discussion and I have wondered the same thing. My lights have one channel with 450nm and 470nm lights that are the most intense. But my second channel that has white, red, and green also has the 420nm UV light. This channel gets run very low. So how important is the 420nm light for growth?

I think, and I may be wrong, but corals will grow with only blue spectrum but will grow optimally when whites, reds, and greens are added to the mix. Additionally the other colors can make the reef more appealing to the eye so it does not look like your are looking at your reef through a windex bottle. I see many people have success running blackbox style lights with blue spectrum 100% and the W,R,G spectrum at 1-10%

James M · Mar 14, 2019

!!!!^^^

Dana Riddle · Mar 14, 2019

skimjim said:
Did some deep reading on light spectrum and what's best for corals.

PLZ go easy on me bc I'm not very TECHY. Amateur understanding.

Here's what I learned:

* visible light for corals range from VIOLET (around 380nm'ish wavelength) to RED (700nm'ish wavelength)

* WHITE LIGHT is the entire spectrum 380nm to 700nm being dispersed at the same time. Never knew that.

* sweet spot for corals is mainly 420 to 460nm which is variations of blue wavelengths. Minor sweet spots are a little bit of green (500nms) and a little red (600-700nms)

QUESTION:
1) If you basically BLASTED your corals with 400nm to 470nm blue light, would that pretty much be sufficient for coral growth and health?

2) What's the use of WHITE light? Aren't you blasting corals with the entire spectrum with too much unneeded green, yellow, red at high levels?

Question #2 is my biggest question

.

White light is mostly for aesthetic appeal but green light up to about 550nm is absorbed and used in photosynthesis by the accessory pigment peridinin (found in zooxanthellae and diatoms.) Red light is also useful in photosynthesis but without it, fish and some coral colors are unimpressive. It is a common misconception that yellow and orange light is not used in photosynthesis - it is, but is absorbed in much lower rates than others (blues and reds.)

b4tn · Mar 14, 2019

@Dana Riddle when it comes to W,R,G lights what PAR is optimal? I am getting a PAR meter from my club and would be kind of cool to adjust each light channel by par vs par of all lights together. Or does it not work that way?

Rybren · Mar 14, 2019

FWIW, here is a graph from one of Dana's articles showing the light spectrum at 10 feet deep in sea water. There's much more green, orange and red than there is in the spectrum from a typical light fixture.

Blackice615 · Mar 14, 2019

Following

b4tn · Mar 14, 2019

Rybren said:
FWIW, here is a graph from one of Dana's articles showing the light spectrum at 10 feet deep in sea water. There's much more green, orange and red than there is in the spectrum from a typical light fixture.

Interesting. Most of the lights I have seen are heavy in the 450 spectrum with a few 470's. This chart shows the 4701-480 the strongest of the blue and green is way up there.

But is the OP chart what coral actually uses and this chart whats found if you put a sensor under the water?

Rybren · Mar 14, 2019

Dana's chart is from a sensor 10 feet underwater and showing the spectrum of sunlight at that depth. The OP chart looks to me to be pretty close to the spectrum produced by a light fixture. I don't think that I've seen a graph of the spectrum for photosynthesis.

PatW · Mar 14, 2019

Rybren said:
FWIW, here is a graph from one of Dana's articles showing the light spectrum at 10 feet deep in sea water. There's much more green, orange and red than there is in the spectrum from a typical light fixture.

In the Caribbean, I generally don’t see corals any shallower than 15’. I have seen really nice stag horn in the lagoon at Turneffe atoll at 12’. At deeper than 15’, there is 0 red light. I have seen invasive lion fish which are bright red and at depth they look black. I took a photo using strobes of a queen angel in front of a rock wall that looked grey. It was at 80’. When I looked at the photo the rock wall was covered with encrusting sponges that were lurid oranges and reds. At depth, like 80’, everything is blue and green.

Dana Riddle · Mar 14, 2019

Here's a chart showing spectral quality of 'green' coastal water (the 'cleanest' of any Jerlov Coastal water) and likely that seen off the east coast of Florida.

Dana Riddle · Mar 14, 2019

And a Table showing photo-saturation points for various corals. The deeper the depth, the lower the Saturation Point. And then we must account for spectral quality. As aquarists, we want simple exact answers. Unfortunately, there are none. All this info demonstrates the incredible adaptability of zooxanthellae.
Saturation
Acropora divaricata 77
Acropora granulosa 102
Pavona varians 110
Montipora capitata 135
Acropora nobilis 180
Montipora tuberculosa 180
Acropora millepora 190
Montipora danae 'Superman' 200
Porites cylindrica 200
Stylophora pistillata 200
Pocillopora damicornis 225
Acropora millepora 230
Porites lobata 250
Acropora cervicornis 281
Montipora tuberculosa 300
Acropora microphthalma 300
Stylophora pistillata 300
Acropora nobilis 310
Pocillopora eydouxi 323
Acropora cervicornis 331
Acropora formosa 340
Acropora gemmifera 340
Acropora digitifera 387
Porites lutea 400
Sinularia densa ~207
Tridacna maxima >600

Bpb · Mar 14, 2019

Consider this...are you really hoping to achieve that level of efficiency by trying to pinpoint ONLY the specific wavelengths that measure a response? In doing this on an led fixture you’re saving peanuts in electricity and sacrificing the actual RENDERING of color, especially in sps type corals.

Some may disagree but the shotgun approach of providing plenty of everything seems more desirable. You won’t run into deficiencies, and your color rendering will be at its maximum ability based on your lighting. The reason low kelvin bulbs in the 6500-10,000k range for halides and tubes are so effective. There are zero spectral deficiencies.

So what if a few watts are wasted on light that is only reflected. What is wasted biologically is desirable aesthetically. Consider what is visually appealing also. I can definitely say in my own tank experience that I achieve better color development, rendering, and better growth when offering a full spectrum light to the animals, even if some of it isn’t used biologically.

ZoWhat · Mar 14, 2019

Crap!

OP here..... so the chart I posted is the light spectrum on my four LED lights

@Dana Riddle .... so are you saying I should add LED lights that go heavier on GREEN 550nm diodes? I'm pretty good at swapping out and soldering in replacement diodes. I could add a whole bank/row of 550nm diodes to complement the 420, 460 I'm heavy on.

Thoughts????

.

Dana Riddle · Mar 15, 2019

skimjim said:
Crap!

OP here..... so the chart I posted is the light spectrum on my four LED lights

@Dana Riddle .... so are you saying I should add LED lights that go heavier on GREEN 550nm diodes? I'm pretty good at swapping out and soldering in replacement diodes. I could add a whole bank/row of 550nm diodes to complement the 420, 460 I'm heavy on.

Thoughts????

.

Some green wouldn't hurt (maybe 505nm LEDs)but can't state that they would be worth the trouble. The first commercial LED array (PFO's Solaris) had a few green LEDs and we were able to keep corals at low PPFD values. I've always *thought* the green light was at least partially responsible. There is no doubt that zoox can utilize green light.

Dana Riddle · Mar 15, 2019

Dana Riddle said:
Here's a chart showing spectral quality of 'green' coastal water (the 'cleanest' of any Jerlov Coastal water) and likely that seen off the east coast of Florida.

I should have noted this is at a depth of 10 meters (about 40 feet.)

ZoWhat · Mar 15, 2019

Just bought these puppies to solder a row of then into each of my four LED boxes. They are 500nm cyan wave length

So......

I've completely retrofitted the 4 LED boxes I use for my Zoa/Paly dominated tank

Per light box/fixture:
* qty 18 - 420nm 3 watters
* qty 18 - 460nm 3 watters
* and now coming soon qty 8 - 500nm 3 watters

Cant wait to see how grow and color of zoas/palys are effected

.

b4tn · Mar 15, 2019

skimjim said:
Just bought these puppies to solder a row of then into each of my four LED boxes. They are 500nm cyan wave length

So......

I've completely retrofitted the 4 LED boxes I use for my Zoa/Paly dominated tank

Per light box/fixture:
* qty 18 - 420nm 3 watters
* qty 18 - 460nm 3 watters
* and now coming soon qty 8 - 500nm 3 watters

Cant wait to see how grow and color of zoas/palys are effected

.