LEDs... Have they arrived?

[sirreal63]

As well as the numerous reports of corals changing colors or the colors not looking right and slower growth.

 

[mussel and hate]

If the corals grow at a rate comparable to how they do in natural light and with similar structure I don't think the gaps matter. Aesthetics are subjective and need to be considered aside from growth, but this is one of the areas where gaps in spectrum are telling.

I think one of the chief benefits of LED is the lack of certain portions of the spectrum, particularly IR and UV.

@ Beananimal: I'm kind of confused by the efficiency claims of the DOE chart and maybe I'm not interpreting it correctly once again, but please bear with me. Cree claims their XT-E royal blue produces >500mw of flux @350ma and ~3ish V, which would be about 50% efficient right? Why then the claim of 20-30%? Perhaps this is a generalization made for average white LEDs?

 

[BeanAnimal]

bottom line: what does ones tank look like and how do the corals grow...if there are wavelength gaps but the lights grow corals just fine whats the issue?

I would venture to say that MOST of the fixtures out there DON'T grow most corals just fine, though many may grow some coral just fine. The list of products or builds that DO grow a broad range of corals well certainly appears to be growing though.

Assuming for a moment that growth is not the issue, many of us just don't care for the color rendering that most fixtures offer. In fact, I have only seen a few that I like at all

 

[sirreal63]

Bean, I know you were visiting some led fixtures, and the ReefTech was one of them. Was it the model that just started shipping recently or one of the older models?

 

[meshwheel]

Boy, just when you "THINK" led's are "IT", more debates and reported problems!!!!
I am still running my metale halide 250 watt 14K and love it!
I have a feeling LED's have a 5-10% intensity drop every year. Furthermore, they are full of arsenic and other dangerous materials.
I am stil liking the Kessil 15Kpendants and may give em a try for my new 65 gallon reef I am building. They look great!

 

[nyquist]

I have a feeling LED's have a 5-10% intensity drop every year

Furthermore, they are full of arsenic and other dangerous materials.

where did you get this from?

 

[PolyReef]

Very interesting conversation gentlemen.We start comparing very technical details about LED lamps.many of technical aspects of LEDs. are still in the newborn age.......
Like before with the older version of the lights we can probably spend many hours to argue between us. for me the most important is when I purchased my LED is:
Rapid growth of my corals
Full control of the lamps
Customer service I can rely on.
Comparing the Brand X or Y for me doesn't make no sense. every company who makes those lamps have their own way. some provides us with that one thing and some provide us with another. Only different is how much we pay for the LEDs lamps and if we receive what we Are promised......
Is no secret in industry that very few companies achieve the full customer satisfaction.
They work very hard to provide the best product they can. Looking at reef central posts we can judge very quickly who is a leader in this industry. personally I would be not surprised many of reef folks Will make their own LED lamps and have much more wider knowledge then Some one to be producers of LEDs lamps......
That is still a lot of work to do to make those lamps perfect. very few companies
Have capability to do this. and New product require strong new-product developing team of specialists and people with high credentials ,unfortunately very few companies can afford spending huge amount of money.
Happy Reefing

 

[nyquist]

@ Beananimal: I'm kind of confused by the efficiency claims of the DOE chart and maybe I'm not interpreting it correctly once again, but please bear with me. Cree claims their XT-E royal blue produces >500mw of flux @350ma and ~3ish V, which would be about 50% efficient right? Why then the claim of 20-30%? Perhaps this is a generalization made for average white LEDs?

cree claims around 300 lumens of flux, not mW of flux, on their XML chips at 700mA @ 2.9V. That is ~150lm/W, which is ~22% of an ideal 555nm source.

Cree also published 254 lm/W in an R&D lab setting, which is around 37% of the same ideal 555nm source.

 

[BeanAnimal]

If the corals grow at a rate comparable to how they do in natural light and with similar structure I don't think the gaps matter. Aesthetics are subjective and need to be considered aside from growth, but this is one of the areas where gaps in spectrum are telling.

I agree

I think one of the chief benefits of LED is the lack of certain portions of the spectrum, particularly IR and UV.

At first blush I would tend to agree, but then again who knows. There are a lot of variables and some amount of IR and UV may be of some benefit. I don't know if enough is known.

@ Beananimal: I'm kind of confused by the efficiency claims of the DOE chart and maybe I'm not interpreting it correctly once again, but please bear with me. Cree claims their XT-E royal blue produces >500mw of flux @350ma and ~3ish V, which would be about 50% efficient right? Why then the claim of 20-30%? Perhaps this is a generalization made for average white LEDs?

The subject is more than a little complex based on many factors including the LED color and optimal vs real world operating parameters (current, junction temperature, etc). A "white" led is a BLUE led with a white phosphor coating. The coating causes losses in total flux, including Stokes losses (the phosphors robbing some of the photon energy in the process of changing the wavelength) and basic scattering of light due to it traveling through a thick phosphor coating. The "warmer" the white, the more the loss. Different phosphors have different efficiencies...

Drive that particular XT-E BLUE LED at 1/3 of its rated power and and an ideal junction temperature and it is closer to 50% efficient. Add the phosphor (just guessing, but maybe 80% efficient) and real world junction temperatures and you are back in the 40% land. Drive it at 1/2 or more of its rated current and you are back in 30% land

 

[BeanAnimal]

Bean, I know you were visiting some led fixtures, and the ReefTech was one of them. Was it the model that just started shipping recently or one of the older models?

I looked at the current model and the brand new (just started shipping model) but was unable to see it operate, and to be honest could care less about some of the features (clouds, a storm mode with speaker, etc). One neat feature though is the ability to DIM an individual section so that a picky or new coral can have more or less light than the others around it. I DID like the color rendering for the most part. I DID NOT like the price at all and considering I would need (2) of them ,it is just not an option.


@RGibson:

I will be ordering LR from a local guy (Dave's Aquastock) as I refuse to deal with the phosphate issues I had with the dry base rock I used last time.

 

[Dave Thebrewguy]

they are full of arsenic and other dangerous materials.

You might want to look into the materials contained in a fluorescent or MH lamp.
Commercial/industrial facilities are required to send their used lamps for recycling, these usually are shipped as "universal waste-lamp" and require no special handling. Broken bulbs can't be shipped this way, those go as "hazardous waste, debris contaminated with mercury" and must be packaged as per hazardous waste regulations.
I don't recall ever seeing a leaking LED, but if there were one, the CFR's would still allow it to ship as "universal waste-electronic devices." Personally, I'm not too worried about the arsenic that is contained in some diodes (yes, some, not all) but break a couple T5s and I'll be reaching for my respirator.

 

[sirreal63]

Thanks, I think I will know how the latest model works, it will probably be over my tank. I don't care about storms or most of the fluff features, though many do and that is ok, but the light itself appears to be the best available. I have not yet seen the new model, but it just started shipping so that is understandable. It should be no secret that I a a die hard MH proponent, but I also know where the future is heading. Price is usually secondary when you are a sps lover, so the price is not bad if the fixture performs as expected. I have very high hopes for it.

Thanks for your input, it is always valued and appreciated.

 

[BeanAnimal]

Thanks, I think I will know how the latest model works, it will probably be over my tank. I don't care about storms or most of the fluff features, though many do and that is ok, but the light itself appears to be the best available. I have not yet seen the new model, but it just started shipping so that is understandable. It should be no secret that I a a die hard MH proponent, but I also know where the future is heading. Price is usually secondary when you are a sps lover, so the price is not bad if the fixture performs as expected. I have very high hopes for it.

Thanks for your input, it is always valued and appreciated.

The new model does look like it is well built. Modular LED boards, etc. One of our local stores is heavily involved with the product and has received a pile of inventory I guess. The new fixtures were hanging in place of the old ones, but not running, as they were being programmed while I was there. I will go back and take a look sometime this week and maybe see if I can make a deal on the two older fixtures that are soon to also be replaced

 

[sirreal63]

They have not shipped South yet, the East Coast got the first shipment. The previous model is nice but I suspect the latest one will be much more user friendly. I have no doubt the previous model will do all that you want, but I have to have the latest one, I want to test the ability to grow Acro's under it and not give anything up. If my suspicions are right it will do the job nicely. Having the iPad control will be nice too. I hate the iPad but I confess I am using it more and more than annything else lately and being to play with the lights from the sofa will be a nice feature.

If you get a chance to see the latest model when it is hooked up and running, let me know how you like it compared to the previous model. I would really be interested in how it differs. It is my understanding that they reworked everything to make it better.

 

[Stolireef]

Some of us don't look back at vinyl with anything more than love. It is 30 years later and we still have not found a way to fill in the gaps using digital audio. The 3rd (and greater) order harmonics and continuous tone of vinyl audio have no match even today. Same can be said for tube vs solid state amplification, etc.

I am rather sure that LEDs will continue to improve, but an arc lamp IS pretty much the same as the sun and by its very physical nature puts out a similar spectral profile with NO gaps. It can be made to produce peaks or humps with different halids and phophors, but it is a full spectrum arc to begin with. LEDs will rely ONLY on phosphors due to the laws of the universe that make them work.

Do corals NEED the full spectrum? It appears that maybe they don't. But I do agree that we are still missing some of the needed peaks or even valleys that LEDs don't cover.

While I do miss my vinyl (album art is a lost art form), I do enjoy the convenience and flexibility of MP3s. Unfortunately, as my kids will tell you, I can't hear anything annoying so the quality of digital audio works for me. That said, I completely agree with you BA that LED's aren't my cup of tea. Had them, worked really really hard (and spent beaucoup $$) trying to love them, but in the end, I guess I'm just an old fashioned vinyl guy.

BA, I will give you a little jab however about arc lighting being the same as natural sunlight. You are way more skilled and experiened than I am so I assume you meant that MH's fill in areas of wavelength similar to how natural sunlight does rather than comparing how MH generates light to fusion. Then again, thanks to you, I pulled out my old turn table and I'm listening to ELO's Out of the Blue. It doesn't get much better than when I add a tumbler of scotch to the evening.

 

[Stolireef]

While I do miss my vinyl (album art is a lost art form), I do enjoy the convenience and flexibility of MP3s. Unfortunately, as my kids will tell you, I can't hear anything annoying so the quality of digital audio works for me. That said, I completely agree with you BA that LED's aren't my cup of tea. Had them, worked really really hard (and spent beaucoup $$) trying to love them, but in the end, I guess I'm just an old fashioned vinyl guy.

BA, I will give you a little jab however about arc lighting being the same as natural sunlight. You are way more skilled and experiened than I am so I assume you meant that MH's fill in areas of wavelength similar to how natural sunlight does rather than comparing how MH generates light to fusion. Then again, thanks to you, I pulled out my old turn table and I'm listening to ELO's Out of the Blue. It doesn't get much better than when I add a tumbler of scotch to the evening.

Oh, and btw, now I feel really really really old.

 

[KCombs]

I would venture to say that MOST of the fixtures out there DON'T grow most corals just fine, though many may grow some coral just fine. The list of products or builds that DO grow a broad range of corals well certainly appears to be growing though.

Assuming for a moment that growth is not the issue, many of us just don't care for the color rendering that most fixtures offer. In fact, I have only seen a few that I like at all

That's a reasonable answer ... and thanks ya'll for replying, esp. with those mannered answers

 

[BeanAnimal]

I assume you meant that MH's fill in areas of wavelength similar to how natural sunlight does rather than comparing how MH generates light to fusion.

Yes, the context was the light being a true "full spectrum" as the result of a plasma, not the way the plasma is generated

Then again, thanks to you, I pulled out my old turn table and I'm listening to ELO's Out of the Blue. It doesn't get much better than when I add a tumbler of scotch to the evening.

I still collect vinyl... mostly punk rock. Got rid of most of the classic rock save a few rare items like first pressings of some Kiss and Zep, etc. I also have some wondeful old 78's from the likes of Freddie Slack, etc. and a decent pile of classical stuff, and some soundtracks like victory at sea, etc.

 

[mussel and hate]

cree claims around 300 lumens of flux, not mW of flux, on their XML chips at 700mA @ 2.9V. That is ~150lm/W, which is ~22% of an ideal 555nm source.

Cree also published 254 lm/W in an R&D lab setting, which is around 37% of the same ideal 555nm source.

I really did mean >500mw flux for the XT-E RB as opposed to lumen output from whites. This is pretty impressive because a 50% efficient high PAR blue light source with a focus <180° presents some serious advantages over traditional reef lighting technologies. MH may edge it slightly but the reflective losses from a 360° output probably set them even. LED efficiency is likely to improve comensurate with Moore's too...

@Beananimal: I suspected as much regarding the DOE chart being specific to white LEDs with their Stokes shift losses. I think the 20-30% number doesn't take into account the latest top drawer emitters running at peak efficiency.

There could be some benefit from a touch of IR and/or UV. I know some studies suggest otherwise but as far as I'm concerned the jury is still out on this one. I know I enjoy the feel of sunshine perhaps my corals do too.

 

[nyquist]

I really did mean >500mw flux for the XT-E RB as opposed to lumen output from whites.

oh yes, I totally misread what you had said; the chart posted earlier was for white light sources, and those percentages are taking into account the phosphor losses that the blue leds don't have to worry about

LED efficiency is likely to improve comensurate with Moore's too....

there is no doubt that LEDs will continue to improve in efficiency, but they are capped (unlike many technologies Moore's law is being applied to) by the internal quantum efficiency as well as limited output versus input power; i.e. they will get better but obviously can't get better than 100% and it will likely be a slow trek to near-100%

@Beananimal: I suspected as much regarding the DOE chart being specific to white LEDs with their Stokes shift losses. I think the 20-30% number doesn't take into account the latest top drawer emitters running at peak efficiency.

I think the chart was more focused on talking about typical values, and even most top-notch efficient white LEDs at really low drive current will struggle to beat 30%

There could be some benefit from a touch of IR and/or UV. I know some studies suggest otherwise but as far as I'm concerned the jury is still out on this one. I know I enjoy the feel of sunshine perhaps my corals do too.

very true; don't some corals respond the same way to UV as many other animals, by producing extra pigment to block UV radiation?