LEDs... Have they arrived?

[James77]

Well, not quite. While it's true that heat is an extremely common waste energy, not all of the power inputted to those devices gets converted to heat on any reasonable time frame in your room. Much of the optical power is converted into chemical energy in the form of chemical bonds between and inside sugars, calcium coral structures, fibrous plant materials, etc produced by the photosynthetic organisms. So a 100W space heater will surely end up heating your room more than a 100W light fixture when taking into consideration chemical energy storage.
But I'm sure the heat misconception is primarily driven by the whole radiative versus conductive heat topic

Nope. The 100 watt light fixture will put the EXACT amount of heat a 100 watt heater would.

I think you would find far less energy is absorbed into corals than you are thinking. Even then, it is as stored energy or energy used by a living organism which will give off heat. It has been argued to death, and it is really quite simple.

 

[BeanAnimal]

well you can't release more heat than is taken in so 100W of LEDs will not release more than 100W of direct heat, but something probably closer to 60 or 70W

Yes it was a typo. 60W-70W is correct

Well, not quite. While it's true that heat is an extremely common waste energy, not all of the power inputted to those devices gets converted to heat on any reasonable time frame in your room. Much of the optical power is converted into chemical energy in the form of chemical bonds between and inside sugars, calcium coral structures, fibrous plant materials, etc produced by the photosynthetic organisms.

Correct, but in context to the total amount, the portion of energy converted and stored is not relevant

Why won't LEDs have full spectrum? Wouldn't a mix of phosphor coated warm white, cool white, and neutral white give a peak on the blue end with a pretty wide hump reaching from teal to red?

It is my understanding that the propor phosphors don't exist in a stable form for this purpose and the super narrow output of the emitters complicates the issue. I guess time will tell.

 

[BeanAnimal]

I am assuming that was a typo and you meant 25 watts of heat.

Yes, it was a typo.

A 100W LED will produce (directly) somewhere in the neighborhood of 70W of heat that has to be wicked away by the heatsink.

Well each of those devices turns 100 watts of electricity into 100 watts of another form of energy, so 100% of their electric energy - % efficency = heat generated. So a 100 watt LED setup with 75% efficency will pump out 25 watts of heat and the rest is light,

And the light strikes objects and turns to heat

a 60% efficency fan will turn 40% of its electricity into heat (another reason I like huge passive heatsinks) and the rest into kinetic energy,

That moves air and other things in the room and causes friction (heat) and sound that is absorbed by things in the room (more heat). It all turns to heat

 

[nyquist]

Correct, but in context to the total amount, the portion of energy converted and stored is not relevant

except it is relevant, the energy used to create fibrous matter, or the coral's physical structure, or other relatively permanent organic compounds does not produce heat (until broken down by decomposition, which will not occur in your tank in any sort of reasonable timeframe).

You can say energy is conserved, yes it is a physical law; while all heat is energy, all energy is not heat, which is what you seem to be trying to say

 

[BeanAnimal]

This brings me to another thing that I think most of the LED proponents and fans don't quite understand:

We are starting to see more and more folks talk about "full spectrum" builds and there is a misconception that because we can blend a few colors and SEE full spectrum, that the light itself is full spectrum. That is, a red and green led focused through a lens will appear to the eye as a yellow point source, but a spectral graph shows NO yellow, and ONLY a RED and a GREEN peak.

Put 5 colors of LEDs in a fixture and you get 5 peaks with nothing in between, not a full spectrum light source even if our eyes see it as full spectrum

 

[nyquist]

Nope. The 100 watt light fixture will put the EXACT amount of heat a 100 watt heater would.

I think you would find far less energy is absorbed into corals than you are thinking. Even then, it is as stored energy or energy used by a living organism which will give off heat. It has been argued to death, and it is really quite simple.

I think you understand the concept, but you're not hearing what I'm saying:

the 100W devices put out the same amount of energy, yes, but some of the light energy does NOT make it to heat in this system. Yes the light helps the algae produce sugars, which are used up by the coral, but for what? to bond Ca ion and compounds into organic molecules to build their solid structures. It takes energy to make such bonds and harnesses energy in, for all intensive purposes in a reef tank, permanent calcium based structures. While it is a small amount, it means that the light does NOT produce the exact amount of heat the heater does.

 

[nyquist]

This brings me to another thing that I think most of the LED proponents and fans don't quite understand:

We are starting to see more and more folks talk about "full spectrum" builds and there is a misconception that because we can blend a few colors and SEE full spectrum, that the light itself is full spectrum. That is, a red and green led focused through a lens will appear to the eye as a yellow point source, but a spectral graph shows NO yellow, and ONLY a RED and a GREEN peak.

Put 5 colors of LEDs in a fixture and you get 5 peaks with nothing in between, not a full spectrum light source even if our eyes see it as full spectrum



You can take an RGB light source and mix the light to trick the brain (due

but put warm white, cool white, and neutral white together and guess what you get from all those magical phosphors?

TONS of time and effort is being poured into LEDs to deliver top notch CRI, with this, the phopshors are being tweaked so they more accurately match the sun's natural light output

 

[BeanAnimal]

except it is relevant, the energy used to create fibrous matter, or the coral's physical structure, or other relatively permanent organic compounds does not produce heat (until broken down by decomposition, which will not occur in your tank in any sort of reasonable timeframe).

It is not relevant because the amount of energy we are talking about is a tiny fraction of the whole.

So out of that 100W of light, the portion that is converted and stored is a tiny tiny fraction. At the same time those living organisms are converting and storing energy, they are also burning calories to survive. That is they are at near a steady state with regard to their thermal energy intake and output, with the non steady state portion being ONLY the daily tissue and skelatal growth.

Like I said, the fan blows paper and dust around the room. Some of that dust or a piece of paper lands in a spot higher than it started. That is stored energy (potential energy) that is not converted to heat until the paper or dust finds its way back to the level it started... It is simply not worth talking about in context to the total 100W the fan converted

You can say energy is conserved, yes it is a physical law; while all heat is energy, all energy is not heat, which is what you seem to be trying to say

No, that is not what I am saying. I am saying FOR OUR PURPOSES, all of the energy transformed by these devices is converted to heat in the local environment almost as fast as it is converted to work. There is no argument that SOME of it is stored. The point is that not enough of it is stored to say that they devices differ in the real world heat they impart to the "room". Thats all

, it means that the light does NOT produce the exact amount of heat the heater does.

No, not EXACT, but close enough in the context what is trying to be demonstrated by the example. See again the comment above regarding the "steady state". Sure some energy is used to grow algae and that is exported before it is turned to heat, some is stored in the tissue and skeleton etc, etc. It is just that in the context of the 100W (for example) that amount is a tiny fraction.

Every time this subject comes up, somebody wants to split hairs and explain that SOME of the light is converted. If we really want to split hairs, we can also bring in the concept of entropy.... Lets not split hairs

 

[James77]

I think you understand the concept, but you're not hearing what I'm saying:

the 100W devices put out the same amount of energy, yes, but some of the light energy does NOT make it to heat in this system. Yes the light helps the algae produce sugars, which are used up by the coral, but for what? to bond Ca ion and compounds into organic molecules to build their solid structures. It takes energy to make such bonds and harnesses energy in, for all intensive purposes in a reef tank, permanent calcium based structures. While it is a small amount, it means that the light does NOT produce the exact amount of heat the heater does.

No, I hear you fine

What percent of the energy we pump into lighting do you tink actually makes it into the coral or algae? It is such a miniscule amount, that it is not even really worth mentioning. It would have zero noticeable effect on heat in our tanks by adding what they use back in.

 

[Stolireef]

This brings me to another thing that I think most of the LED proponents and fans don't quite understand:

We are starting to see more and more folks talk about "full spectrum" builds and there is a misconception that because we can blend a few colors and SEE full spectrum, that the light itself is full spectrum. That is, a red and green led focused through a lens will appear to the eye as a yellow point source, but a spectral graph shows NO yellow, and ONLY a RED and a GREEN peak.

Put 5 colors of LEDs in a fixture and you get 5 peaks with nothing in between, not a full spectrum light source even if our eyes see it as full spectrum



You can take an RGB light source and mix the light to trick the brain (due

Precisely my point on LED's. I think there is a flavor missing between the wavelengths. I've noted this in several posts and it is why I'm switching back to MH/T5 from Radions. That said, give it five or ten years and I believe we will all be looking back on 'analog' light in the same way we look at vinyl albums in audio. Other than missing spectrum, LED's have it all over MH/T5.

 

[nyquist]

It is not relevant because the amount of energy we are talking about is a tiny fraction of the whole.

So out of that 100W of light, the portion that is converted and stored is a tiny tiny fraction

Do you know how much energy is required to convert the readily available nutrients into more algae and plant and coral? I don't, but I can do some unit conversions to approximate it. Think of how many Calories are in 1 gram of sugar: 4 Calories (with a capital "C", meaning kilocalories).
So for the sake of simplifying the calculations, assuming 1g of coral/algae/plant growth ~= 1g of sugar produced: if you have a corals that grow @ 1 kg per month, that is 33g per day.
33g of sugar/day ~= 132 kcal/day
132 kcal/day = 6.4 watts

yes the calculations are rough, but the idea is steadfast, it takes a LOT of energy to create chemical bonds


and your situation was a hypothetical one, I was just stating the hypothetical facts

 

[BeanAnimal]

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.

 

[nyquist]

Precisely my point on LED's. I think there is a flavor missing between the wavelengths. I've noted this in several posts and it is why I'm switching back to MH/T5 from Radions.

but, but!

but put warm white, cool white, and neutral white together and guess what you get from all those magical phosphors?

TONS of time and effort is being poured into LEDs to deliver top notch CRI, with this, the phopshors are being tweaked so they more accurately match the sun's natural light output

the spectrum from phosphors on new white LEDs is relatively good, there's not a ton missing outside of the teal range

 

[RGibson]

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.

Bean thank you for the help with the rock.

 

[mussel and hate]

So no offense (I really do mean that) to the poster....but I see this type of post a lot. Posts like this simply crack me up, basically saying that any joe schmoe can build a LED system more efficiently that a professional business set up to design and build a product.

I absolutely agree that some LED products are total junk, but that's a LIFE statement. What about Cars, TV's, Food....anything? If you pay for quality, you get quality simple as that. Do you think that anyone who bought a Gremlin thought that the automobile wasn't ready for primetime?

Now, I also agree that the knowledge to use the LEDs effectively can be less that intuitive, but the gains can be vast.

I'll use myself as an example. I have a 150G (30" deep) and I have two x Radion MP30w lights. When I first got them I just tuned them on, used a basic profile and off I went. I noticed my Birdsnest and Acro's started to lose a bit of color. Reason - I was blasting them with so much light I was bleaching them.

Then I did a little research on the Ecotech forum and a couple of people had seen great success by dropping the Reds and Greens in the spectrum. I did that, and within 3 days i'm at about 60-75% color regeneration. The actual growth of the SPS has taken off like nuts, but the color suffered a little until I got the lights dialed in.

All my fish, softies etc are looking better than they ever did under MH.

So....if you want to purchase LEDs, then research the specific product array. Don't buy a shitty $200 light fixture, that's not adjustable/customizable for intensity and spectrum contribution, and complain that LEDs suck. Yes, to get into the high end stuff costs money, so traditional MH, T5, PCs or combinations there of make sense for some people...but you'll more than pay for a decent LED fixture in your power bills, or chiller cost to keep the tank cool with the MH lighting.

The Radions (and now a few other high end fixtures) 100% go down to the 420-450nm light range, but they are expensive. Doesn't mean they aren't ready for the hobby, just means if you want leading edge technology, you pay for it. Same with Plasma TVs, then LED TVs and now back to Plasma when they came out.

Unless you've had experience will ALL the LED products on the market...you cannot say "LEDs aren't ready for primetime"...it's simply not a fair and reasonable statement.

It's all about choice. Pay your money, take your choice and be prepared to learn something new everytime you think you've got it all licked.

Matt.

I just got back to this thread and while I'm not offended at all and I'm glad I'm enertaining I still feel the need to comment..

LED technology is up to the task and I voted such in the poll, however the potential of the technology isn't being exploited fully in contemporary designs. Sure they grow coral. I had success growing corals with normal output daylight fluorescent tubes and 5500K MH bulbs back in the '80s, that doesn't mean those light sources were ideal.

You can turn your radion's reds and greens up or dim them all you wish but it won't do anything for the amplitude or spectrum of blue light in the mix. Only adding more LEDs with different spectral peaks will do this. Radions employ Cree XP-E blue and XP-E Royal blue emitters which is one more variety of blue that most commercial arrays provide but that's still just two peaks in the blue and nothing below 450nm.

Contrast the Radion with the average 'full spectrum' DIY build with Blue, RB and 420nm near UV for an example of what is possible with currently available off the shelf parts.

The DIY builds on this forum are leading the industry towards better products. These are the hotrods of the LED scene. Hobbyists are pushing the boundaries not the commercial manufacturers.

 

[jerpa]

but, but!


the spectrum from phosphors on new white LEDs is relatively good, there's not a ton missing outside of the teal range

You don't get full spectrum from one LED however. They all lack the IR and UV component of full spectrum lighting. Is adding a UV, neutral white, and deep red LED together the same to the coral as getting it from one source? I dont think we know the answer to that.

 

[srf11]

Bean - I wasnt trying to rile anyone up - truthfully.

I respect that you're currently not a real fan of LEDs - all your prerogative.

I am more and more. Can they be improved? 100% yes.

Did I pay too much for the Radions?? 100%!! lol

It's ok - this is a fun hobby

 

[mussel and hate]

This brings me to another thing that I think most of the LED proponents and fans don't quite understand:

We are starting to see more and more folks talk about "full spectrum" builds and there is a misconception that because we can blend a few colors and SEE full spectrum, that the light itself is full spectrum. That is, a red and green led focused through a lens will appear to the eye as a yellow point source, but a spectral graph shows NO yellow, and ONLY a RED and a GREEN peak.

Put 5 colors of LEDs in a fixture and you get 5 peaks with nothing in between, not a full spectrum light source even if our eyes see it as full spectrum

Your spot on BA. However if enough peaks are represented(and adequately broad) full spectrum can be achieved. This is my concern with contemporary commercial designs. There just arent enough peaks.

 

[KCombs]

Ive been following the backnforth and I'm impressed at the intelligence on both sides....
Still Ive been in my share of these...
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?

 

[nyquist]

if there are wavelength gaps but the lights grow corals just fine whats the issue?

probably CRI/visual appeal