Metal Halide vs. LED Rates of Photosynthesis

[Nonya]

The ocean surface is rough, so refraction distorts light creating bright 'shimmer' lines in shallow water. A reef tank with good surface flow and a single metal halide will produce a similar affect. A VHO light over a tank is too diffuse to form these shimmer lines. LEDs are somewhat in the middle, individual LEDs are point sources and can be close enough together to produce shimmer lines, but not as strong as halides.

Since I got into reefing 25 years ago, people have claimed that the shimmer lines briefly expose coral to much brighter light than it normally would, and this is beneficial. I haven't seen any good evidence for this, and it certainly isn't necessary, as most wild coral is too deep for shimmer lines . It is also a matter of personal preference - I find the lines distracting looking at my tank a long time, but other people like that look.

I read that the brief exposure to higher PPFD can also exceed photoinhibition levels.

 

[Nonya]

I'm curious - what exactly is 'shimmer' and how is it produced more by MH than LED?

It's a matter of personal preference, but shimmer is a real thing. Point light sources produce a lot, although it can produce much more shimmer than in the ocean. Clustered LEDs can also produce shimmer. T-5s have zero.

 

[Bpb]

Try shooter's glasses. They make the blue less noticeable, while maximizing the POP.

I actually know people who wear Orange glasses at home and have tried to hand me some when I walk in. I cannot think of a more ridiculous way to reef. So stupid

 

[Nonya]

And there you go with the salacious comments again. 14,18 and 20k do not produce brown coral pigmentation.

Definition of salacious: Having or conveying undue or inappropriate interest in sexual matters.
Hmm.

 

[Nonya]

I actually know people who wear Orange glasses at home and have tried to hand me some when I walk in. I cannot think of a more ridiculous way to reef. So stupid

It prevents nausea for some, LOL.
Actually, it can also filter out wavelengths known to cause retinal damage over time.

 

[MnFish1]

It's a matter of personal preference, but shimmer is a real thing. Point light sources produce a lot, although it can produce much more shimmer than in the ocean. Clustered LEDs can also produce shimmer. T-5s have zero.

Yes - it was kind of a rhetorical question. My 'guess' - is that its not very important other than aesthetically in our tanks. Most of it though IMHO. does not come from the 'light' as compared to the wave flow on the surface - though I can see where a small difference could be seen

 

[oreo54]

Since I got into reefing 25 years ago, people have claimed that the shimmer lines briefly expose coral to much brighter light than it normally would, and this is beneficial. I haven't seen any good evidence for this, and it certainly isn't necessary, as most wild coral is too deep for shimmer lines . It is also a matter of personal preference - I find the lines distracting looking at my tank a long time, but other people like that look.

Yep no proof as to benefits and totally subjective. as to nature ..wait for it.. first MH/Led then t5..



Later on Coralcare and SKY..
Depending on surface agitation of course.



Care to guess the PAR difference between the caustic lines and background here?
Starts at a different time.

 

[Bpb]

It prevents nausea for some, LOL.
Actually, it can also filter out wavelengths known to cause retinal damage over time.

….or just not run solid blue light if you don’t like it

 

[Nonya]

Yes - it was kind of a rhetorical question. My 'guess' - is that its not very important other than aesthetically in our tanks. Most of it though IMHO. does not come from the 'light' as compared to the wave flow on the surface - though I can see where a small difference could be seen

Sorry. I figured you knew after seeing the summary of your posts.

I agree things tend to smooth out farther down.

 

[Nonya]

….or just not run solid blue light if you don’t like it

That doesn't make sense. If they don't like it, they'll never run it in the first place. People who run heavy blue lights do it because they like it (and because it promotes photosynthesis and intense coloration).

 

[djf91]

I actually know people who wear Orange glasses at home and have tried to hand me some when I walk in. I cannot think of a more ridiculous way to reef. So stupid

Yep. This whole thing with LEDs has become more of an arcade experience than recreating an accurate depiction of a coral reef.

Crit, grab the laser tag guns!

 

[Nonya]

Try shooter's glasses. They make the blue less noticeable, while maximizing the POP.

Should I have said "shooting" glasses?

 

[Nonya]

Yep. This whole thing with LEDs has become more of an arcade experience than recreating an accurate depiction of a coral reef.

Crit, grab the laser tag guns!

I don't think all of the people using LEDs over thousands of dollars of corals would agree with you. It's about health, pigmentation, growth, spectrum control, energy savings, thermal control, and most importantly--POP! Love that POP!

The only guns I use are real.

 

[Bpb]

That doesn't make sense. If they don't like it, they'll never run it in the first place. People who run heavy blue lights do it because they like it (and because it promotes photosynthesis and intense coloration).

Then I misinterpreted the just wear orange glasses suggestion as advice on how I could enjoy my tank under heavy blues all the time

 

[Nonya]

So I was wondering. Corals in nature experience

Then I misinterpreted the just wear orange glasses suggestion as advice on how I could enjoy my tank under heavy blues all the time

I have my LEDs programmed for varying spectra from dawn to dusk, somewhat simulating actual lighting on real reefs. Mid-day is closer to the AB+ with more white, but no red/green. The rest of the day is a transition from/to dawn and dusk, with all blue and violet. If I'm going to spend too much time looking at the tank, I usually wear eye protection. BTW, the eye damage can come from any bulb with a strong blue spectrum.

 

[areefer01]

Later on Coralcare and SKY..

What is the context for these two lights specifically? I'm not sure I understand the context.

 

[oreo54]

What is the context for these two lights specifically? I'm not sure I understand the context.

Different types and degree of shimmer based on "pointyness" of overall array.
The SKY and Coralcare have a few "beaming" diodes while most are diffused.
Soo between the 2 extremes.

In nature from exteme shallow water caustic lines to completely flat at depth (or sometimes weather conditions)

Anyways still all personal preference. For those that like the flat 2d look of t5's no "evidence" will it nor should it sway them as long as they are happy with the results.

 

[areefer01]

Different types and degree of shimmer based on "pointyness" of overall array.
The SKY and Coralcare have a few "beaming" diodes while most are diffused.
Soo between the 2 extremes.

In nature from exteme shallow water caustic lines to completely flat at depth (or sometimes weather conditions)

Anyways still all personal preference. For those that like the flat 2d look of t5's no "evidence" will nor should it sway them as long as they are happy with the results.

Thank you for clarity. This is a very busy thread so wasn't sure and wanted to ask. As a scuba diver, previous user of Kessil a360x, and a current SKY user I can see your point.

 

[Midrats]

So I was wondering. Corals in nature experience

I have my LEDs programmed for varying spectra from dawn to dusk, somewhat simulating actual lighting on real reefs. Mid-day is closer to the AB+ with more white, but no red/green. The rest of the day is a transition from/to dawn and dusk, with all blue and violet. If I'm going to spend too much time looking at the tank, I usually wear eye protection. BTW, the eye damage can come from any bulb with a strong blue spectrum.

My eyes are totally effed then

 

[Nonya]

My eyes are totally effed then

From what I read, it isn't necessarily rapid, and research continues. Blue light is much more energetic than the rest of the visual spectrum, which is why they're researching that part of the spectrum.