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UV LED's?


dylanserbin

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What is the purpose of people putting UV LED's into their arrays?

 

They do so in attempt to get more of that end of the spectrum hoping it will help the growth of their corals usually. Some might enjoy the look they give their tank and inhabitants i guess too. I've not found any solid information that adding UV benefits or harms corals. Just as with most LED configurations its some tried and true along with some tweaking via speculation.

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corals naturally create some of the colors they have in order to protect themselves from UV lighting, UV is only for the look of the coral, they will not be any healthier i beleive

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From liveaquaria:

 

Color change due to UV light

In nature, ultraviolet light waves (UVA and UVB) penetrate the ocean's surface but are filtered out as the light travels through the water. Both UVA and UVB light waves have been found to cause destruction of DNA and RNA within coral tissue. In response, many corals have made adaptations to reduce the effects of these harmful rays. These corals developed protective pigments that are often blue, purple, or pink in color. Most corals that contain these pigments come from shallow waters where the amount of UV-A and UV-B light is higher than in deeper areas of the reef.

 

In home reef aquariums that rely on metal halide lighting, it is important to protect corals from UV light. Coral without these protective pigments as well as shallow water corals that may have lost their pigments during transportation are especially susceptible to the effects of UV light. Fortunately, preventing any UV light from entering the aquarium is as simple as employing glass aquarium canopies and making sure the protective glass lens on the metal halide fixture is properly installed.

 

It is not uncommon for corals with these bright colors to adjust to the lower UV-A and UV-B conditions found within home aquariums. The loss of colorful pigmentation is not necessarily a sign of an unhealthy coral - it is simply a normal coral adjusting to its new environment.

 

Conclusion

It is a common misconception among many hobbyists that color changes in newly received coral is an indication of unhealthy coral. Many times the color change is merely the result of corals adjusting to the new lighting intensity, spectrum, and change in UV light. With this in mind, it is important to consider the color of newly received corals and research their lighting requirements when placing corals in the aquarium.

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so basically Dont do UV LED's?

 

 

and don't do drugs either lol

 

 

 

 

I'm about to set up my tank with led and I don't have uv, so I gonna find out what heppens. I personally feel that there not needed

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so basically Dont do UV LED's?

 

I don't think that's the lesson learned here. With proper acclimation there could be potential gains to be had by running UV. The problem is, there is no set amount of UV light to use and people are really still experimenting with it. The research papers I've read all seem to conclude that the coloration of coral seems to be directly related to UV exposure and is a genetic mutation that helps protect their supporting algea.

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so basically Dont do UV LED's?

i drew the opposite conclusion from that text. it seems that we want some UV's to enhance colors in our corals, but not too much as to hurt them. without UV rays they may have more bland colors b/c they don't need that pigment to protect them anymore.

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From liveaquaria:

 

Color change due to UV light

In nature, ultraviolet light waves (UVA and UVB) penetrate the ocean's surface but are filtered out as the light travels through the water. Both UVA and UVB light waves have been found to cause destruction of DNA and RNA within coral tissue. In response, many corals have made adaptations to reduce the effects of these harmful rays. These corals developed protective pigments that are often blue, purple, or pink in color. Most corals that contain these pigments come from shallow waters where the amount of UV-A and UV-B light is higher than in deeper areas of the reef.

 

In home reef aquariums that rely on metal halide lighting, it is important to protect corals from UV light. Coral without these protective pigments as well as shallow water corals that may have lost their pigments during transportation are especially susceptible to the effects of UV light. Fortunately, preventing any UV light from entering the aquarium is as simple as employing glass aquarium canopies and making sure the protective glass lens on the metal halide fixture is properly installed.

 

It is not uncommon for corals with these bright colors to adjust to the lower UV-A and UV-B conditions found within home aquariums. The loss of colorful pigmentation is not necessarily a sign of an unhealthy coral - it is simply a normal coral adjusting to its new environment.

 

Conclusion

It is a common misconception among many hobbyists that color changes in newly received coral is an indication of unhealthy coral. Many times the color change is merely the result of corals adjusting to the new lighting intensity, spectrum, and change in UV light. With this in mind, it is important to consider the color of newly received corals and research their lighting requirements when placing corals in the aquarium.

 

 

Pay attention to the bold section. The paragraph above it makes it sound like all UV is blocked from using UV glass (almost all glass has UV blocking properties). This is not the case. UV glass only stops UV-C, but only reduces UV-A and UV-B. Sanjays spectral plots of MH bulbs (SE and DE with UV glass) all show small spikes of UV-A, typically around the 350-380nm range, with it increaseing around 395nm as it ramps up into the visible light range. I have seen this myself with my own spectrometer readings.

 

so basically Dont do UV LED's?

 

Don't use them yet. The ones that are typically in the cost range for the average hobbyist won't do you any good. They aren't in the right wavelength, and don't have the power to do much good. The right UV LEDs that will offer the best results are unfortunately very expensive at this time. We also don't 100% know what wavelength will be best, and how much output we need. I am starting to experiment with some of this, but it's slow going.

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I've noticed some of my zoanthids getting duller with my leds. I was considering adding some uvs to bring the color back. Do you recommend any evil?

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That's the thing. I don't know enough about the LEDs that are available to safely recommend something. Plus, they are expensive. They start at $50 each and rise sharply. It's not something that I would recommend to beginners. I'm sure it would be pretty dissheartening killing a $50+ LED. Chances are, we would only need one to cover a large area if we can find one with enough output.

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That's the thing. I don't know enough about the LEDs that are available to safely recommend something. Plus, they are expensive. They start at $50 each and rise sharply. It's not something that I would recommend to beginners. I'm sure it would be pretty dissheartening killing a $50+ LED. Chances are, we would only need one to cover a large area if we can find one with enough output.

 

I'm building an LED set that includes Violet wich is right smack between UV and actinic @ 405nm. Its a little bit ghetto but Its about 6watts worth of plain old round LED's for 1sqft. Pretty cheap ...lots of work. I just plain couldn't find much 450nm and less in high power. They generally don't even make purple...I guess they figure the blue is already low enough power as is. I don't know if I'll be using all 6watts worth but I figure no matter how inefficent they are 6w worth should be "enough" ..shrug.

 

I'm hoping we don't have to actually dip into(or far into) the UV spectrum to get what we are after. All usual LED builds even with royal blue cree's have pretty much no output under 430nm and the blues under 440nm. I've heard some people rave about the color and some are content while some are very unhappy. My hope is that we are just a hair off the right spectrum for the color we want.

 

The LED i'm getting at 405nm rough guess at 50% output should be +/- 10nm so 395-415nm and 25% output should be +/-20nm 385-425nm.

 

I'm curious what anyone thinks about it. I have the stuff ordered but have to wait for it to get here(from china of course).

PM me if your experimenting with UV and would like to swap notes as we go and maybe learn from each other to help speed things up.

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6W isn't going to be a good measurement of the lighting potential. That's only the energy it consumes. Typically, the smaller the LED, the lower the efficacy, and the lower the emitted light power will be. As an example, I'm working with a 5W and a 3W 365nm LED. The 3W LED actually puts out about 25% more light at the maximum current for both LEDs.

 

I'm not saying don't try it. I'm just saying that your mileage may vary. Dealing with the LEDs you are using, you should be safe from damaging corals. The LEDs I'm using could be a different story, even though I'm using less input energy.

 

Also, your spectral half width should not be changing with current. At least not as much as you are claiming. +/- 10nm is fairly average for that type of LED, but not much more.

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I've got 2 18w power compact actinic bulbs along with my leds. Is there a uv power compact bulb I could use to get the uv spectrum?

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6W isn't going to be a good measurement of the lighting potential. That's only the energy it consumes. Typically, the smaller the LED, the lower the efficacy, and the lower the emitted light power will be. As an example, I'm working with a 5W and a 3W 365nm LED. The 3W LED actually puts out about 25% more light at the maximum current for both LEDs.

 

I'm not saying don't try it. I'm just saying that your mileage may vary. Dealing with the LEDs you are using, you should be safe from damaging corals. The LEDs I'm using could be a different story, even though I'm using less input energy.

 

Also, your spectral half width should not be changing with current. At least not as much as you are claiming. +/- 10nm is fairly average for that type of LED, but not much more.

 

I am well aware that the 6w consumption is far from much of an output measurement and the cheap LED's efficacy is probably crap. I wanted to go this route since its dirt cheap. I can get them higher powered..but as you know they are not exactly free tho not as bad 365nm.

 

I'm not saying the "spectral half width" is changing with current. I'm talking about the relative radiant power. 405nm is the dominant wave length and at 405nm its relative radiant power is 100%. The same LED throws off 395nm and 415nm as well but at only 50% of the power that it puts out 405nm. right?

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I've got 2 18w power compact actinic bulbs along with my leds. Is there a uv power compact bulb I could use to get the uv spectrum?

Closest thing you are going to find is a true actinic blub (420nm). UV PCs are typically limited to UV ranges that we really don't want.

 

I am well aware that the 6w consumption is far from much of an output measurement and the cheap LED's efficacy is probably crap. I wanted to go this route since its dirt cheap. I can get them higher powered..but as you know they are not exactly free tho not as bad 365nm.

 

I'm not saying the "spectral half width" is changing with current. I'm talking about the relative radiant power. 405nm is the dominant wave length and at 405nm its relative radiant power is 100%. The same LED throws off 395nm and 415nm as well but at only 50% of the power that it puts out 405nm. right?

I think I see what you are talking about. At +/- 5nm, you have maybe 50% of the relative intensity at those wavelengths (as an example). The input current doesn't change. Still, +/- 20nm seems really wide.

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I've not seen any datasheets for anything under 450nm so you'd have a better idea of the range than I would. I was merely speculating based on the data I took from the nearest blue data i recently saw. If its closer to what your saying +/- 5mm at 50% then at %25 its probably closer to +/- 10nm instead of 20.

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it makes the fluorescent color POP.

not sure if its worth it growth wise.

 

also visually its minimal cuz your eye cant really see the UV only like 3% of it.

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I'm building an LED set that includes Violet wich is right smack between UV and actinic @ 405nm. Its a little bit ghetto but Its about 6watts worth of plain old round LED's for 1sqft. Pretty cheap ...lots of work. I just plain couldn't find much 450nm and less in high power.

 

FYI, they have the ecoxotic stunner strips in 403nm.

 

CJ

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it makes the fluorescent color POP.

not sure if its worth it growth wise.

 

also visually its minimal cuz your eye cant really see the UV only like 3% of it.

 

Why does everyone assume this is for growth? It's not. If you have been paying attention to any of the comments I've made about UV usage over the last year, you would see that I have always talked about coloration (not just fluorescent "pop" either) and overall coral health. I couldn't care less if it makes colors fluoresce. I just want to make sure that the normal colors for the corals are represented correctly. This could be the trick for those not happy with the overall coloration of their corals.

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Why does everyone assume this is for growth? It's not. If you have been paying attention to any of the comments I've made about UV usage over the last year, you would see that I have always talked about coloration (not just fluorescent "pop" either) and overall coral health. I couldn't care less if it makes colors fluoresce. I just want to make sure that the normal colors for the corals are represented correctly. This could be the trick for those not happy with the overall coloration of their corals.

 

I wonder if coral does weird stuff with UV light, almost like Quantum Dots... they have to absorb the energy somehow, as just reflecting UV wouldn't work. maybe they're shifting UV light in the spectrum. Now THAT would be cool.

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This is a really interesting thread. It's hard to find info on how UV affects corals. Plenty of papers on theory but very little personal testimony from reef keepers.

From my understanding so far, it seems that corals create chromoproteins to mitigate exposure to the otherwise harmful UV rays. As humans, we do exactly the same thing by tanning. So perhaps we should apply tanning methodology to increase the colors of our corals. By placing intense UV-A, and some UV-B for a few minutes per day we could stimulate the color without doing much harm to the DNA/RNA.

AND the best part about this theory is that we can test it using cheap human tanning lights, (cheap compared to reef aquarium supplies that is B) )

Any thoughts on this?

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