The use of UV light in LED

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merereef

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Just sharing my experience. Although we may not be able to visually see certain spectrums,corals especially sps love the spectrum and utilize it to its fullest potential.

I feel like this is a mixed battle. Everyone will say something different. But as for percentages,I usually run my violets (if they are separate from my royals) about 15-20% lower. Because,violets will burn coral and output A LOT of par so just be careful.

I like using the leds I have to have a broad range spectrum,regardless if its white,royals,violets. Broader of a spectrum,better colors !!!

Thanks for sharing see this is what i mean we need someone to run tests
 

oreo54

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Question- the ocean depth of the coral. Red light is filtered the deeper you go. So how much of what color is actually reaching that coral in nature? I think for optimum growth we would need to figure out and recreate the natural lighting scheme for each coral?


uschio14000k.JPG




Ushio 14000k mh 250W and light measured at various ocean depths..
Sadly stops at 700nm but you can find others.
Thing is, EVEN IF you emulated the depth you want would you like the way it looks?
 

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uschio14000k.JPG




Ushio 14000k mh 250W and light measured at various ocean depths..
Sadly stops at 700nm but you can find others.
Thing is, EVEN IF you emulated the depth you want would you like the way it looks?

he hit the nail here. So many people trying to provide only specific peak wavelengths, terrified to “waste” light on wavelengths not directly used. A light that only targeted 3-4 specific photosynthetic peak usage spectra would make for an ugly tank
 

jda

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Tullio Del Aquila has some points in his "Facts of Light" presentation a few MACNAs ago that nearly all that we keep in this hobby is collected on one breath. Not all and some stuff is collected in the air at low tide, and some stuff is deeper. It is Ok to assume that 3m is as deep as nearly anything that we have in our tanks was collected at.

We saw dudes in waist deep water cutting corals from places that looked like this (not my photo):


FWIW - Ushio 14k is a very attractive bulb that nearly everybody likes... kinda like the Phoenix 14k. It really pops without being too windex-y.
 

hart24601

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UV diodes do seem to be improving. Here is the 380nm on my orphek after 1.5 years of running full blast 6hr a day. No damage to it or the lens.

i did have 440s the overheated and orphek sent me a whole new board despite being out of warranty so was curious how the UVs held up.

2E4733C4-4FBD-4DB0-A8D2-648AF3393CE1.jpeg
 

hart24601

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OK so violet and ultra violet are not the same thing.
violet Wavelength: 380–450 nm
ultra violet Wavelength: 380nm and below...some charts 400 and below.

I was under the impression ultra violet light (UV) was under 400nm by definition.
 

oreo54

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I was under the impression ultra violet light (UV) was under 400nm by definition.
Depends on who's defining it apparently..
The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light. A typical human eye will respond to wavelengths from about 380 to 740 nanometers
https://en.wikipedia.org/wiki/Nanometers

Spectrum is continuous no matter..399.99ect..

Ultraviolet light
is a form of radiation which is not visible to the human eye.
By that definition, it may depend on which human.. ;)

Seeing UV Light
Most people cannot see ultraviolet light, however, this is not necessarily because the human retina can't detect it. The lens of the eye filters UVB and higher frequencies, plus most people lack the color receptor to see the light. Children and young adults are more likely to perceive UV than older adults, but people missing a lens (aphakia) or who have had a lens replaced (as for cataract surgery) may see some UV wavelengths. People who can see UV report it as a blue-white or violet-white color.



Insects, birds, and some mammals see near-UV light. Birds have true UV vision, as they have a fourth color receptor to perceive it. Reindeer are an example of a mammal that sees UV light. They use it to see polar bears against snow. Other mammals use ultraviolet to see urine trails to track prey.
 
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LARedstickreefer

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How do we know that the corals get better use out of a near UV led vs another RB led? I’d rather just have another RB led than a near UV.
 

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blasterman

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Blue light between 400-470nm is just energy to a coral and doesn't differentiate growth. Chlorophyll doesn't work on specific wavelengths of light either but is a broadband energy converter. Biologists have been debunking this for years, but the reef industry in an attemp tp push 10 channel lights on customers has muddied the science.

True UV-A and UV-B which are well below 400nm have always been a mystery and debated to for years in the marine biology area, but you can't control it anyways so its an essoteric debate. Halides and T5's do have true ultraviolet emission, but again, there's not much data on this in terms of coral growth and if anything halide makers try to filter as much of it as possible for safety reasons. Most UV in a T5 is blocked by the phosphor.

This leaves violet (395-420nm), which has increasingly been marketed in LED reef lights when in fact it's not proven to do much of anything other than make heat. Those same ultraviolet LED's sold in $800 reef lights are the same ones sold on Amazon for $30 party blacklights. Same LED. I have 50watt 395nm LED chips in a box. I don't use them on my reef tank because they don't do anything.

If you look at a spectrum of an LED reef light with "UV" LEDs (it's technically not UV, but 395nm is a common hit point for LED manufacturing) the amount of actual energy being emitted by those "UV" LEDs is trivial. Chlorophyll utilizes this enrgy, but in no different way than regular 450nm. LED light makers are just trying to make something up to push their lights.

I've spoke directly with PhD's on this and they all laugh their butts off at the "UV" myth. The irony is even if you could light a tank with a spectrum that's balanced like the sun your tank would be so brown and ugly you would get rid of it.
 

oreo54

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For what it’s worth here is @Dana Riddle analysis of orphek uv leds. He can probably go into greater detail about if uv is of value.
Here's an action spectrum for a Favia coral. Unfortunately, I did not include radiation below 400nm, although chlorophylls a and c2 can absorb radiation down to about 350nm. As a footnote chlorophyll a has a shoulder abosrbance at ~383nm. As for coloration, there are only two or three fluorescent pigments that are maximally excited by UV-A/violet radiation. As for coloration, In some cases, this radiation will be beneficial. In photosynthesis, it will be helpful. Is it necessary - no.

We can (not) ignore successful reef tanks that have no (or very little) UV-A/violet light.


Post#20
 
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merereef

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Blue light between 400-470nm is just energy to a coral and doesn't differentiate growth. Chlorophyll doesn't work on specific wavelengths of light either but is a broadband energy converter. Biologists have been debunking this for years, but the reef industry in an attemp tp push 10 channel lights on customers has muddied the science.

True UV-A and UV-B which are well below 400nm have always been a mystery and debated to for years in the marine biology area, but you can't control it anyways so its an essoteric debate. Halides and T5's do have true ultraviolet emission, but again, there's not much data on this in terms of coral growth and if anything halide makers try to filter as much of it as possible for safety reasons. Most UV in a T5 is blocked by the phosphor.

This leaves violet (395-420nm), which has increasingly been marketed in LED reef lights when in fact it's not proven to do much of anything other than make heat. Those same ultraviolet LED's sold in $800 reef lights are the same ones sold on Amazon for $30 party blacklights. Same LED. I have 50watt 395nm LED chips in a box. I don't use them on my reef tank because they don't do anything.

If you look at a spectrum of an LED reef light with "UV" LEDs (it's technically not UV, but 395nm is a common hit point for LED manufacturing) the amount of actual energy being emitted by those "UV" LEDs is trivial. Chlorophyll utilizes this enrgy, but in no different way than regular 450nm. LED light makers are just trying to make something up to push their lights.

I've spoke directly with PhD's on this and they all laugh their butts off at the "UV" myth. The irony is even if you could light a tank with a spectrum that's balanced like the sun your tank would be so brown and ugly you would get rid of it.

Wowwww... so this explains why red sea and others use low uv and voilet... crazy then why some like ecotech suggest to increase the uv to 100... i loved your in depth explanation.. so in your eyes would you say uv(led manufacturers call) and voilet is not absolutely necyto run at 100% as its most likely marketing?
 

oreo54

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.. crazy then why some like ecotech suggest to increase the uv to 100... so in your eyes would you say uv(led manufacturers call) and voilet is not absolutely necyto run at 100% as its most likely marketing?

Well PART of this is the fact that most throttle the other colors back so much (all light nm participates) that your PAR levels drop..

Say what you want about violet and related it still contributes to photosynthesis.

I'd keep that in mind.

Marketing.. well think they'd sell more or less lights without it?
 

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Its not about what corals need its about what they can convince you that you need. Example protien skimmers...look at all the threads about which ones work and are some worth triple the price...I have news for you in the 80s I had a protien skimmer back when you had to order them as local stores didn't even know what they were. It hung on the back ran off a powerhead you attached with a 3/4 inch flexible line and then you hooked a whisper air pump to it with 2 wooden air stones (made smaller bubbles) and a drain line that you ran to a bucket. Your control was a manual $1 valve on the air line. Thing looked like someone made it out of spare acrylic at home depot...it worked amazingly well and did exactly what it was supposed to do. No moving parts and only the lid came off allowing you to change the air stones.
Now look at today...oh you need this shape, this air plate, this pump, all these valves...or else all your fish will die...that's what they want you to believe.
 

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