The myth of LED efficiency

[boodlefish]

Keep in mind that my main complaint is efficiency....take a look at the bottom of this article at the wattage needed to run these fixtures.

The aquaillumination fixtures uses 75 watts and is a 12" x 12" square,this is the fixture that shows the best results when tested.

^^^ you go from Sanjay's article; here to some random example of a different (older) AI light below. I'd assume that some one who wants to compare the "latest and greatest" would have the common sense to post accurate and or relevant data.

I thought this was very interesting....
Power Consumption: up to 100W per 12"
That means that this fixture draws 600 watts of power!!! And this is the fixture that Sanjay said performed well! AGAIN where are the energy savings! Please note that these guys are the professionals and know much more than ANY of us on these forums when it comes to LEDs, if they thought that 1/2 the amount of LEDs would perform well in a reef tank they would sell a 3 light fixture for a 72" tank. PLEASE NOTE THAT A 1000 WATT LUMATEK BALLAST USES 750 WATTS!!! Here's the deal, they are basing these figures off of old magnetic ballasts and are not considering the more efficienct digital ballasts that have been available for years

I know that 12 might seem excessive but I was running 1200 watts over a 175 and my corals LOVED it, if I were experimenting with LEDs I would have to go with a 12 light fixture (or (2) 6 lights). I want my lighting to be intense b/c I want my corals to grow as much as they can. My thinking is that whether you have 100 corals or one, or if you can grow them 1/4" a month or 1" a month, tank maintenance is still the same no matter what, it only costs more in electricity. But I never would have used these LEDs b/c with 12 I would be using more power (1500 watts) than the (3) 400 watts over my tank which was consuming about just under 1000 watts of power.

I'm not sure how much better I can state my case than this.

Uh? math fail? assuming you are still comparing the old Ai's 12 units at 100w each and you come up with 1500 watts? When I learned multiplication 12 * 100 = 1200 but hey I will happily confirm this with my 10 year old neighbor if you need a second opinion.

so if you are getting to use the "latest and greatest" MH digital ballast to get 3 x 400w at 1000w then use the new Ai's at 74w and at 12 x 74w you get 888w. Guess what 888w is less than 1000w even in your ridiculously skewed comparison LED's are 12% more efficient.

I would like to see you put 12 Ai modules over your 175G and see what happens to your corals. "Dracula in the sun comes to mind" You will be cooking your corals on the spot. If you don't believe me then try it.

so now if you went with the Ai recommended 6 what kind of wattage are we looking at? 6 x 74w = 444 huh that would be how much more efficient then your 3 x 400w? Uh LED's in this case are 55.6% more efficient then your MH+ digital ballast.

"I'm not sure how much better I can state my case then this"-
Uh this is the first thing you have said that I agree with. You can't state your case any better, because you have NO CASE. All you have is a hand full of fallacies and, as another Texan would call it, some "fuzzy math."

 

[jcolletteiii]

...some "fuzzy math."

+1*10^8!:rollface:

 

[docstomper]

Internets... srs bizniz.

 

[Greenmaster]

Keep in mind that my main complaint is efficiency....take a look at the bottom of this article at the wattage needed to run these fixtures.
http://www.advanceda...10/5/aafeature2

The aquaillumination fixtures uses 75 watts and is a 12" x 12" square,this is the fixture that shows the best results when tested. Because of the small footprint of the directional LED lighting if I wanted to use this fixture to grow coral over a 150 gallon tank (2' x 6' long) I would need 12 of them for complete coverage of the tank, the same coverage that I would get from MH. Well added up this is 900 watts...that's more than a 1000 watt lamp!!! Ok lets say you only use 6 fixtures instead only placing them down the center of the tank, that's still 450 watts WHICH IS THE SAME POWER USAGE OF DUAL 250 WATT LAMPS! Where are the energy savings? If you think that 12 or even 6 of the LED fixtures don't make heat as much heat as MH that simply isn't true, remember wattage = heat. Now the big question is will 12 of these fixtures out perform a 1000 watt lamp? Will 6 of these out perform a dual 250 watt? Keep in mind that is just to be equal power usage, the advantage of LEDs is that they use LESS power for the same results. So if you think that (3) of these LED fixtures will out perform a dual 250 watt setup I think there is no way just b/c of the small foot print alone.

Now with all that has been said I'm not sure where to start... First thing I have to point out from the quote above "...remember wattage = heat." That is 100% false. Wattage equals power consumption. With lighting wattage minus efficiency equals heat. If a 100w light, is 15% efficient, you have 85w of heat generated and 15w of light (not necessarily all in lumen if it was that would be 10245 lumen).
Some things about MH's, they produce both the heat at the bulb and the infrared that heats whatever the light hits. That's one of the big reasons that PAR goes down so much in water with MH's the red end of the spectrum doesn't penetrate water very well... it get's absorbed (turned into heat).
Green plants don't use much of the blue end of the spectrum while red plants will. If your testing on lights was with a Japanese Red Maple you would find that most LED's would way out perform MH and HPS.
If you look at corals you don't see much that are blue there are some but the majority are not blue.
The color you see from something is the visible part of the spectrum that is not being absorbed. So a red algae or plant or coral would benefit more from a blue light then a red one. And a purple coral would more benefit from yellow and red. Green needs the deep purple and the reds. Now just because something is green or red or blue it doesn't mean that it is reflecting all of that spectrum just a portion of it.
Generally speaking the further the corals natural habitat is from the surface of the water the less red it naturally would get. But just because a coral likes it near the top doesn't mean that it needs red (or that lower down it could live without red).
There is so much misinformation and opinions on here it's hard to know what to respond to.
The plasma has real world lumen per watt of between 50-70 (for aquarium use) MH has an even broader range depending on so much but it's around 65-115 (for aquarium use it is around 70 and goes down from there). And LED's that I have seen are 50-120. But the new ones are around 100 (in the 1w diodes) I am buying a bunch of LED's for my tank (a 320g VERY DEEP tank) they are 20W chips (20, 1w diodes on one piece of silicone) and they get 1600 lumen per chip (80W per lumen)
But as has been stated Lumen is light within a specific spectrum and not what corals or plants need. It's what we can see. So it's not extremely relevant it's just one of those things that we can use to "compare the fruit from different plants."
Now I BELIEVE that LED's produce a spectrum better suited for home aquariums then MH's I also BELIEVE that they are better suited for their thermal impact on the aquarium. (True statement) LED's produce less light in the infrared/red spectrum.(these numbers are not of an actual light it is just to help visualize the lighting efficiency issue) So a 100w MH producing 8000 lumen is 11% Luminous efficacy and produces 89w of heat/non visible spectrum. The same would be true with an LED but of that 89w of heat/non visible light (not sure the exact numbers because not all LED's are the same) 90% or more would be heat at the base unit as electrical resistance. In a MH only about 40% of that heat is at the base of the unit. The rest is radiated into the tank. I would not say that LED's are for everyone. If you have to heat your tank year round even with the lights on, then MH would be your best option at the moment (LED tech is still growing and will possibly one day blow MH out of the water... no pun intended) But IMO If you have problems with heat and have to run a chiller most days when the lights are on I would say LED's are your best option. I warn though, try to get similar LED wattage, maybe slightly less, then your current MH wattage because LED's are not that much more efficient (yet) it's just where the heat is... Also LED's are extremely sensitive to heat. You must have adequate cooling or they will have a very short lifespan.

 

[greenbean36191]

The color you see from something is the visible part of the spectrum that is not being absorbed. So a red algae or plant or coral would benefit more from a blue light then a red one. And a purple coral would more benefit from yellow and red. Green needs the deep purple and the reds. Now just because something is green or red or blue it doesn't mean that it is reflecting all of that spectrum just a portion of it.
Generally speaking the further the corals natural habitat is from the surface of the water the less red it naturally would get. But just because a coral likes it near the top doesn't mean that it needs red (or that lower down it could live without red).

This is ignoring fluorescence, which is a big part of coloration in corals. Corals with bright green, blue, red, pink, or purple colors are often that color because they re-emit light at that wavelength, not because they're reflecting it. They absorb light at one wavelength, excite an electron, and re-emit a photon at a lower wavelength, which depending on the placement of the pigment could either hit your eye or the zoox. They also tend to use mixtures of FPs of different colors, so a purple coral could be the result of a purple FP or a blue FP and a red FP.

You can't just look at a coral and tell which part of the spectrum it's actually using based on its color. If you could, it would make scientists' jobs a lot easier.

 

[Greenmaster]

This is ignoring fluorescence, which is a big part of coloration in corals. Corals with bright green, blue, red, pink, or purple colors are often that color because they re-emit light at that wavelength, not because they're reflecting it. They absorb light at one wavelength, excite an electron, and re-emit a photon at a lower wavelength, which depending on the placement of the pigment could either hit your eye or the zoox. They also tend to use mixtures of FPs of different colors, so a purple coral could be the result of a purple FP or a blue FP and a red FP.

You can't just look at a coral and tell which part of the spectrum it's actually using based on its color. If you could, it would make scientists' jobs a lot easier.

I was trying to make it as simple as possible so I left out some stuff. Most florescence is violet/ultra violet light that is modified (some absorbed) and re-emitted. That is why people add antics and deep blue LED's. As I stated before that is the end of the spectrum that penetrates water best. I wasn't saying that looking at the color was a way to determine the exact spectrum that you need I was just pointing out that ocean plants have a lot more red's and browns then greenhouse plants. Another thing since you mention it I'll expand it a bit further. You can have something that looks red but still absorbs some red on either side of the frequency that is being reflected. An example is you could have something that reflects at 700nm but absorbs and uses light from 675nm down and 725nm up, (I don't know this as a fact it's just what makes sense to me... it's my theory... I don't have the time or the equipment to test to see exactly what wavelength something emits...). A good way to find out if something absorbs a certain wavelength is to emit light at a specific frequency and if the object is black then it is absorbing all of the light (just because it is absorbing the light doesn't mean it is using it) If the object is reflecting the same wavelength and similar strength that is being emitted, then it is not using that wavelength (if the color/wavelength is changed then it is possible that it is using some of that wavelength).

... and that's why I didn't get too much into it I said a lot but basically didn't say a way to determine what wavelength something needs for photosynthesis, just a way to narrow it down. For that you have to do tests with the species that you want the answer for. Then attempt to have it photosynthesize with a specific wavelength (or missing a specific wavelength as it probably takes more then one part of the spectrum to photosynthesize) and then analyze to see if it did or not. This is just too far beyond the average reefer to be able to do, so I felt is was not that important to get into specifics the first time.

Basically all I was trying to do in the first post is help people to understand that in a general sense LED's (which lean to the blue end of the spectrum) can work for most aquarium life, but not so well for most land plants. Also that LED's and MH's are about equal for most reef applications, just one helps to warm the water and doesn't penetrate as well. I feel like I typed out an essay and am being graded on it... (what class am I in? is it science because I could get more technical... or is it English class and more of a debate essay where technical terms and scientific studies are less important and it's more important to get the point across without boring the reader?... too much.)

 

[dickenscd]

Tanks and Corals Under LED Lighting

Tanks and Corals Under LED Lighting

Please post a picture at the following thread if you have a tank or corals under LED lighting.

http://www.reefcentral.com/forums/showthread.php?p=17361070#post17361070


James

 

[55coolgalreef]

im a led fan i have had all three and led is awesome in my opinion.. don't have sps yet but lps and softies are doing great