Blue Light Quantity

[herring_fish]

I am wondering if there is much knowledge build up about the quantity of blue light in a display tank. With the proliferation of large arrays of LED's, many people are playing with light balances that are non-traditional.

While some people like 14K metal halides or lower and others like 20K's. More people can now settle on things like PAR levels, after K rate corrections, growth vs bleaching etc. Now that white LED's are getting more popular, similar discussions are finding some consensus around PAR and other factors. When we move over to blue lighting I haven't found as much information about blue light.

I posted some time back and got more feedback about brands, countries of origin, construction and other factors. Of course I asked the question in a way that required responses along those lines and they were appropriate for where I was at the time. I was cautioned away from having 50 watt 455nm lamps on a 24 inch deep tank along with MH's but this is getting to specifics. Right now I am starting from scratch so I want to start in general terms before I turn to the specifics. While I still need schooling in that area, I want to get to just the amounts of blue light and perhaps a little about spectrum.

Although I have been reefing for 24 years it's hard to describe what I am looking for because I am so new to this part of aesthetics. Many people like myself like the look of lots of blue LED's. In the presents of good metal arch white or LED white light, it can be hard to get a blue overtone in addition to or over the top of the white. For that reason I think, more is better but that might me a bad idea.

Of course, there is the pop that ultra-violate light can provide to the fluorescing corals but many people also like a balance that is dominated by the deep blue look of Royal Blue.

In addition to something like 420, some of us try to build just the right combination of 450, 455 and 460nm light arrays. To us, they just look brighter, bluer. A large part of this is, in some cases, purely for cosmetic reasons and not for coral growth.

In our old tanks, we didn't add too much white light or we might burn our corals. After allotting space for the white light, we didn't fill every remaining available square inch of space over the tank with actinics. I didn't see much difference between a little and a whole lot but not many people told me not to overdo it with VHO or T5 actinic light. Is some cases we were told not to even include actinic light in our total wattage calculations for optimal, safe growth. Now we can burn corals with 420nm LED's.

Now days you can get LED arrays that have 1, 3, 10, 50 watts per lamp and so on. Additionally, you can put hundreds of LED's in a given fixture. Then there are controllers that change the intensity during the day. Total lighting during the day might be fine while the peaks could be too much.

So "¦. Aside from what kind of blue LED, HOW MUCH BLUE LIGHT IS TOO MUCH?

Of course tank depth is a factor and what kind of coral is important but I hope that I can get some feedback on this side of lighting.

For reference: I happen to be starting a new 180 gallon tall tank from scratch (72''Length x 31''Tall x 18''Deep). I plan on having a mixed reef. I plan on getting an "œappropriate amount of white light be it MH's or LED's or both. I am now starting to design my DIY lighting and a little help would be appreciated.

I think you in advance.

 

[trueblackpercula]

I think you bring up some very good questions and I am also looking to find out? I do run my tank more on the blue side and only have 14k for about 2 1/2 hours at peak durning the day.

 

[that Fish Guy]

I am wondering if there is much knowledge build up about the quantity of blue light in a display tank. With the proliferation of large arrays of LED’s, many people are playing with light balances that are non-traditional.

While some people like 14K metal halides or lower and others like 20K’s. More people can now settle on things like PAR levels, after K rate corrections, growth vs bleaching etc. Now that white LED’s are getting more popular, similar discussions are finding some consensus around PAR and other factors. When we move over to blue lighting I haven’t found as much information about blue light.

I posted some time back and got more feedback about brands, countries of origin, construction and other factors. Of course I asked the question in a way that required responses along those lines and they were appropriate for where I was at the time. I was cautioned away from having 50 watt 455nm lamps on a 24 inch deep tank along with MH’s but this is getting to specifics. Right now I am starting from scratch so I want to start in general terms before I turn to the specifics. While I still need schooling in that area, I want to get to just the amounts of blue light and perhaps a little about spectrum.

Although I have been reefing for 24 years it’s hard to describe what I am looking for because I am so new to this part of aesthetics. Many people like myself like the look of lots of blue LED’s. In the presents of good metal arch white or LED white light, it can be hard to get a blue overtone in addition to or over the top of the white. For that reason I think, more is better but that might me a bad idea.

Of course, there is the pop that ultra-violate light can provide to the fluorescing corals but many people also like a balance that is dominated by the deep blue look of Royal Blue.

In addition to something like 420, some of us try to build just the right combination of 450, 455 and 460nm light arrays. To us, they just look brighter, bluer. A large part of this is, in some cases, purely for cosmetic reasons and not for coral growth.

In our old tanks, we didn’t add too much white light or we might burn our corals. After allotting space for the white light, we didn’t fill every remaining available square inch of space over the tank with actinics. I didn’t see much difference between a little and a whole lot but not many people told me not to overdo it with VHO or T5 actinic light. Is some cases we were told not to even include actinic light in our total wattage calculations for optimal, safe growth. Now we can burn corals with 420nm LED’s.

Now days you can get LED arrays that have 1, 3, 10, 50 watts per lamp and so on. Additionally, you can put hundreds of LED’s in a given fixture. Then there are controllers that change the intensity during the day. Total lighting during the day might be fine while the peaks could be too much.

So …. Aside from what kind of blue LED, HOW MUCH BLUE LIGHT IS TOO MUCH?

Of course tank depth is a factor and what kind of coral is important but I hope that I can get some feedback on this side of lighting.

For reference: I happen to be starting a new 180 gallon tall tank from scratch (72’’Length x 31’’Tall x 18’’Deep). I plan on having a mixed reef. I plan on getting an “appropriate amount of white light be it MH’s or LED’s or both. I am now starting to design my DIY lighting and a little help would be appreciated.

I think you in advance.

There is no such thing as too much blue light.

If you talk to any diver they will tell you that the ocean is blue (Not White) and the deeper down you go the bluer it gets.

Alot of the High End Corals are found down deep too (Zoanthids, Acros, Acans, Chalices).

So to mimic their natural enviornment you want blue.

Plus your Corals look so much Nicer.

A lot of people are switching to all blue lighting these days (Myself included).

I have Two LED Tanks that use Kessil A150's 20K Deep Ocean Blue Actinic LED's Only.

I have Two T5 Tanks that use 4 ATI Bulbs which are all Blue Plus.

So to answer your question there is no such thing as too much blue light.

Hope that helps.

 

[trueblackpercula]

There is no such thing as too much blue light.

If you talk to any diver they will tell you that the ocean is blue (Not White) and the deeper down you go the bluer it gets.

Alot of the High End Corals are found down deep too (Zoanthids, Acros, Acans, Chalices).

So to mimic their natural enviornment you want blue.

Plus your Corals look so much Nicer.

A lot of people are switching to all blue lighting these days (Myself included).

I have Two LED Tanks that use Kessil A150's 20K Deep Ocean Blue Actinic LED's Only.

I have Two T5 Tanks that use 4 ATI Bulbs which are all Blue Plus.

So to answer your question there is no such thing as too much blue light.

Hope that helps.

I do t think it was how much blue light but how long to provide blue light. But I could be wrong.

 

[Christian J]

HOW MUCH BLUE LIGHT IS TOO MUCH?

When it harms a particular coral? I think it's safest to be careful with strong blue light. Human eyes are very bad at gauging blue light strength. LED fixtures using various focusing lenses makes it even harder to guess the amount of light the corals receive. Perhaps a PAR meter (if accurate) is the only way to be sure?

 

[herring_fish]

Perhaps a PAR meter (if accurate) is the only way to be sure?

OK Do you have any numbers in mind?

 

[Christian J]

OK Do you have any numbers in mind?

No idea, sorry.

 

[Christian J]

If you talk to any diver they will tell you that the ocean is blue (Not White)

Distant water often looks blue, but that doesn't mean the light close to you is equally blue in color. The light of distant water has been filtered twice: both on its way down from the surface, and then even more on its way towards you after being reflected by some object.

and the deeper down you go the bluer it gets.

Rather the light loses longer wavelengths the deeper you go. At moderate depth it's still mostly white, just with a lack of reds (mostly): http://www.thedivingblog.com/colors-underwater/ --note how the diagram shows red color to be completely absent at 9m/25ft, but red color can be detected by humans as deep as 30m/90ft: http://www.ingentaconnect.com/content/hfes/hf/1972/00000014/00000001/art00008

Even when yellow starts to disappear there's still plenty of green left, making the light more of a ghostly cyan than blue as illustrated here (first photo): http://kona-scuba-diving.blogspot.com/2006/04/heres-underwater-photo-hint-manual.html I suspect most of today's aquarists wouldn't want this kind of "natural light" in their aquarium.

To get "pure" blue light without any green/cyan you need to go much deeper (100m/300ft?) than normal recreational divers. Also note that at this depth even the blue light is much weaker than at the surface: the strongest blue light is found in shallow water (along with the rest of the white spectrum). So you either find strong blue light at shallow/moderate depth together with (at least some of) the other colors, or you'll find a weaker pure blue light much deeper down.

Here's another good read on natural reef light, especially the section on Light Quality halfway down: http://www.fishchannel.com/saltwater-aquariums/aquarium-frontiers/natural-reef-light.aspx

Alot of the High End Corals are found down deep too (Zoanthids, Acros, Acans, Chalices).

Maybe the same species, but actual colonies are normally collected in shallow water. If you do find a deep water colony it will not be used to strong light (regardless of light color), so perhaps you should be extra careful in the beginning.

So to mimic their natural enviornment you want blue.

Plus your Corals look so much Nicer.

They wouldn't look nice in natural deep water light. There would be no fluorescence and very little reflected color too.

A lot of people are switching to all blue lighting these days (Myself included).

Today's aquarium lights are actually white (including reds!) but with lots of extra blue added. This is very different from natural light, which is white with reduced red color (shallow water), cyan (moderate depth) or pure blue (very deep water).

I don't even think you can produce a natural cyan light with the usual combinations of Royal Blue, Blue and Cool White found in today's LED lamps. And even though Royal Blue may contribute to both coral growth and fluorescence, the resulting light color doesn't look even remotely natural to me.

 

[herring_fish]

No idea, sorry.

Thank you for answering the question directly. At least I understand that I have asked the question correctly.

Now please don't get me wrong, I really enjoy the other information and links. It helps me fill in areas that can help me made better design and purchasing decisions. It can help me decide what is a good look for me.

That being said, has anyone see any information that would made me afraid of adding "¦say a thousand watts of blue? "¦or more. Now that might me a ridiculous number, just pulled out of the air but suppose that it was also concentrated on a smaller area.

I guess that this is a bit of an academic question now because it looks like there isn't much hard data on the subject. If there are even subjective observations, I would appreciate anyone sharing them.

Since I started buying LED's for DYI's, I quickly saw that I could have all the light I want. Now it's true that the light spectrums of must LED lamps that are available tend to be clumped into certain spectra as opposed to a much more full spectrum, with peaks and valleys like you get from HD's. That being said, you can get almost anything that you want at an affordable price without too much heat.

Now if I want a dark blue look that is also bright, I could quickly get myself in trouble concentrating too much of a good think in too small of an area, couldn't I?

 

[that Fish Guy]

Thank you for answering the question directly. At least I understand that I have asked the question correctly.

Now please don't get me wrong, I really enjoy the other information and links. It helps me fill in areas that can help me made better design and purchasing decisions. It can help me decide what is a good look for me.

That being said, has anyone see any information that would made me afraid of adding "¦say a thousand watts of blue? "¦or more. Now that might me a ridiculous number, just pulled out of the air but suppose that it was also concentrated on a smaller area.

I guess that this is a bit of an academic question now because it looks like there isn't much hard data on the subject. If there are even subjective observations, I would appreciate anyone sharing them.

Since I started buying LED's for DYI's, I quickly saw that I could have all the light I want. Now it's true that the light spectrums of must LED lamps that are available tend to be clumped into certain spectra as opposed to a much more full spectrum, with peaks and valleys like you get from HD's. That being said, you can get almost anything that you want at an affordable price without too much heat.

Now if I want a dark blue look that is also bright, I could quickly get myself in trouble concentrating too much of a good think in too small of an area, couldn't I?

If a thousand watts of blue does not kill the coral then it is fine.

But most likely if you use a thousand watts (Blue or White) you will probably kill the coral just due to the Crazy High Par you would have unless you hang the Lights like 10 Feet in the Air.

My 55 Gallon uses 4 T5HO Lights that are all Blue Plus and 54 Watts each (216 Total).

 

[jedimasterben]

Now if I want a dark blue look that is also bright, I could quickly get myself in trouble concentrating too much of a good think in too small of an area, couldn’t I?

This is where you run into trouble and will kill your corals. There is no blue light that is bright to the human eye, it is simply phsyics. Human eye sensitivity is as follows:

Royal blue LEDs, which peak between 440-460nm, appear only a few percent as bright as a 567nm 'lime' LED does if both have the same radiometric output. That is a repeatable test - take one Philips Luxeon T royal blue and place it next to a Rebel ES lime. Run at the same current, the blue light will be nearly invisible in comparison to the lime LED.

I use eight Luxeon M royal blue over my 48x24x16 tank at the moment, with 1A max current, equating to around 50 radiometric watts of output (about 92 watts power input, so roughly 55% efficiency). PAR on the bottom of the tank, which is 26" away from the LEDs is between 95 and 125. No lenses.

With all the LEDs and two ATI 39w Blue Plus.

In a typical tank, the intensity you want to shoot for is between 100 and 200 PAR on the bottom of the tank, higher for an SPS dominant tank and lower for certain LPS. Going by these numbers here, that is either over or nearing the maximum output recommended. Giving more PAR doesn't mean getting more growth, sometimes the opposite as the corals then have to reflect as much light as possible or suffer damage.

Now, if I were to run all of my LEDs to get the look that I want (because all blue LED [or all blue any kind of light, etc] just looks like garbage) I would very quickly kill all the coral I put in the tank. To 'fix' this, I keep the LEDs on between 15-30% for white and lime, and around 60% for blue, royal blue, and violet, as peak numbers. My controller does a 5-6.5 hour sunrise and a 5-6.5 hour sunset, so there is no daily peak where all LEDs are at their maximum for more than just a few minutes. The T5 come on for 6 hours daily. This keeps the DLI (daily light interval, basically the total mol of photons) at a decent number, more than enough for my coral and anemones to saturate their zooxanthellae without inhibiting them for any extended periods. This dimming is vital to keeping corals healthy and not struggling to protect themselves from overillumination.


Having a 31" tall tank, you will need more intensity to reach the bottom, as light degrades as an inverse square - double the distance, 1/4 the light, half the distance, four times the light. So with my LEDs at 26" and let's say an average of 100 PAR, at 42" (which is what I'd recommend your LEDs be at) you would only get 38 PAR at the bottom of your tank. So, you would want to use around 24x Luxeon M at 1A over your whole tank to get enough intensity at the bottom, equating to about 150 radiometric watts and around 275 watts of power used. Using other brands of LEDs with lower efficiencies will lead to needing more LED wattage to get the same output, etc.

 

[Christian J]

OK Do you have any numbers in mind?

Found these among my bookmarks (a web search may turn up even more):

http://www.advancedaquarist.com/2002/2/aafeature
http://www.advancedaquarist.com/2009/5/aafeature
http://www.advancedaquarist.com/2007/3/aafeature1

The last article contains a few numbers on saturation and photoinhibition, but of course this varies between species.

I doubt it's practical to try to calculate this when building a light fixture, try to rely on others' experiences instead (and use a dimmable fixture of course).

 

[herring_fish]

Now we are getting somewhere.

Now if I want a dark blue look that is also bright, I could quickly get myself in trouble concentrating too much of a good think in too small of an area, couldn't I?

I knew that it was a dumb thing to say as I was typing it but I wanted to get a response. Thank you

I want to through esthetics out the window for just a moment. So have you arrived at those blue PAR ratings, for your tank, from observing what is too much? Have you burned any corals with blue light?

 

[jedimasterben]

I knew that it was a dumb thing to say as I was typing it but I wanted to get a response. Thank you

I want to through esthetics out the window for just a moment. So have you arrived at those blue PAR ratings, for your tank, from observing what is too much? Have you burned any corals with blue light?

No, because I have a PAR meter and common sense

 

[that Fish Guy]

This is where you run into trouble and will kill your corals. There is no blue light that is bright to the human eye, it is simply phsyics. Human eye sensitivity is as follows:

Royal blue LEDs, which peak between 440-460nm, appear only a few percent as bright as a 567nm 'lime' LED does if both have the same radiometric output. That is a repeatable test - take one Philips Luxeon T royal blue and place it next to a Rebel ES lime. Run at the same current, the blue light will be nearly invisible in comparison to the lime LED.

I use eight Luxeon M royal blue over my 48x24x16 tank at the moment, with 1A max current, equating to around 50 radiometric watts of output (about 92 watts power input, so roughly 55% efficiency). PAR on the bottom of the tank, which is 26" away from the LEDs is between 95 and 125. No lenses.

With all the LEDs and two ATI 39w Blue Plus.

In a typical tank, the intensity you want to shoot for is between 100 and 200 PAR on the bottom of the tank, higher for an SPS dominant tank and lower for certain LPS. Going by these numbers here, that is either over or nearing the maximum output recommended. Giving more PAR doesn't mean getting more growth, sometimes the opposite as the corals then have to reflect as much light as possible or suffer damage.

Now, if I were to run all of my LEDs to get the look that I want (because all blue LED [or all blue any kind of light, etc] just looks like garbage) I would very quickly kill all the coral I put in the tank. To 'fix' this, I keep the LEDs on between 15-30% for white and lime, and around 60% for blue, royal blue, and violet, as peak numbers. My controller does a 5-6.5 hour sunrise and a 5-6.5 hour sunset, so there is no daily peak where all LEDs are at their maximum for more than just a few minutes. The T5 come on for 6 hours daily. This keeps the DLI (daily light interval, basically the total mol of photons) at a decent number, more than enough for my coral and anemones to saturate their zooxanthellae without inhibiting them for any extended periods. This dimming is vital to keeping corals healthy and not struggling to protect themselves from overillumination.


Having a 31" tall tank, you will need more intensity to reach the bottom, as light degrades as an inverse square - double the distance, 1/4 the light, half the distance, four times the light. So with my LEDs at 26" and let's say an average of 100 PAR, at 42" (which is what I'd recommend your LEDs be at) you would only get 38 PAR at the bottom of your tank. So, you would want to use around 24x Luxeon M at 1A over your whole tank to get enough intensity at the bottom, equating to about 150 radiometric watts and around 275 watts of power used. Using other brands of LEDs with lower efficiencies will lead to needing more LED wattage to get the same output, etc.

I disagree completely.

White Light looks like garbage as it makes all the corals look like garbage.

Blue Light makes all the Coral Glow and it Brings Out all their Color.

That is beautiful.

Coral on the Left is under Blue.

Coral on the Right is under White.

 

[jedimasterben]

I disagree completely.

White Light looks like garbage as it makes all the corals look like garbage.

Blue Light makes all the Coral Glow and it Brings Out all their Color.

That is beautiful.

Coral on the Left is under Blue.

Coral on the Right is under White.

Fluorescence and color are NOT the same thing. All corals have color, but not all corals have fluorescence. Even corals with strong fluorescence don't necessarily look better under solely blue light. Keep in mind that only the colors of light that are emitted can be reflected for non-fluorescent colors.

Take a look at this hammer coral. This is under two ATI Blue Plus.

And a red rock flower anemone.

And the same two specimens under 'normal' lighting.

Look at the hammer - would you rather see only the neon green or both the green and non-fluorescent purple? What would a take full of corals with that beautiful purple color look like under all blue light? Nothing, because that color simply wouldn't show up.

 

[herring_fish]

No, because I have a PAR meter and common sense

LOL smart

OK have you made any corals ....well uncomfortable, with blue light?

The reason I keep returning to this is that some people say that blue light is so under utilized by corals that you can hardly have too much. I called one of the leading LED based light fixture manufacturers and the head guy believed that. It doesn't sound very logical to me but many people do believe that.

With the new LED chips, this "œNth degree" question is a reasonable one IMO. For better or worse, I happen to like the bigger chipsets so I could get in trouble with the strong, almost single point, beams that they produce, regardless of how they are focused or defused.

There has got to be a coral that was burnt by blue light somewhere. Have you seen any of your corals get stressed with blue light alone? "¦or did you back off just before you thought that you would reach a tipping point?

 

[herring_fish]

Christian J

Thanks for the articles.

 

[Christian J]

There has got to be a coral that was burnt by blue light somewhere.

Many aquarists seem to report coral burns when switching to LED fixtures. That could be caused by many different things, but considering that blue LEDs are very efficient while at the same time humans are bad at percieving blue light, it seems plausible to me that the aquarist has simply underestimated the strength of the blue light.

I've also seen claims that it's white LEDs that cause burning, but I don't know how people have determined that (have they used white LEDs and no blue?), or why white LED light would cause more burns than say MH light of similar color and strength.

And of course there's a difference between burns caused by a too fast increase in PAR, and PAR levels that are higher than the coral could ever adapt to.

Have you seen any of your corals get stressed with blue light alone?

Tried to find any research on this, but couldn't find much (using keywords like photoinhibition, blue, light).

Here are some experiments with red and blue LEDs, but I didn't find anything about damage from the blue ones in it: http://www.advancedaquarist.com/2003/11/aafeature

Here's an experiment with Stylophora pistillata colonies collected from different depths, that were placed in blue-filtered or natural sunlight(?): http://jeb.biologists.org/content/213/23/4084.full (apparently the experiment only took place for a short time, maybe the colonies would adapt over time).

 

[Christian J]

Christian J

Thanks for the articles.

You're welcome! Here are a couple more I found.

General light theory:
http://www.advancedaquarist.com/2012/10/aafeature

How to build an LED fixture:
http://www.advancedaquarist.com/2014/4/lighting