LED lighting - what ever happened to them?

So I've got to ask...

I've seen at least 10 people now trying out LED lighting as primary tank lighting... The threads always start well lots of info on the systems starting up - but then they drop off the face of the earth.

What's going on here? Are people finding out they don't work? LEDs burning out prematurely? It seems strange that the dozen or so threads I've seen on LEDs as primary lighting have just died out inexplicably - I really wonder why that is.

Mostly I wonder because I've got 100 20,000mcd LEDs to pick up from the post office tomorow (damn taxes), somewhat curious as to where people have been failing - so I can try to avoid the same.

Andy

Really good question, I've been wondering where these guys have disappeared to myself.

IMHO, the failure is in the purity of spectrum.

LEDs are "pure" sources of whatever wavelength light you have.. Remember that corals need more than just the 400-470nm band to survive, they need a little bit of the Yellows and reds.

Although its premature, I think that the only long term LED setup you will see in operation (at least as a DIY'r) will be limited to those who use LED as supplementary lighting.

dga (member here) has a neat design for added light from LEDs, but he correctly states that they are "supplemental".

Hope this helps

Chris

I tried to replace my 96W powerquad with 396 LEDs. At first, I had a 50/50 mix of blues and whites. Bad idea! It was too blue and too dark. I was bummed out about this for about 3 months before I ordered another 100 whites and started unsoldering my blue LEDs to aim for a 75/25 white:blue ratio. About 2 hours and 75 replaced LEDs later... I'm still finding that even though I have better color distribution, the tank still looks dark compared to the powerquad. My corals seemed to react positively to the LEDs despite the tank looking shadowy. I have a 15 tall, so maybe even 396 is not enough to properly light a tank this size. I just did a water change tonight and decided to remove the LEDs from my Aqualight housing. When I put the lights above my old 6g Eclipse, it looks fine. I'll post some pics this weekend.

my guess is that a poster or posters can only review there DIY products for so long as any other idea. either one decides to build the project, modify it to there own liking, uses it for ideas of there own, or passes it off due to the complexity of the design. LED's at this time cannot match in color temperature (spectrum) and intensity of there counterparts (power compact and metal halide) no matter how many one stacks above the tank to keep a vibrant "reef" tank. in my project, i knew by researce that any LED lighting i was to use in my plan, could be for supplemental lighting to the main lights. so my design was based on known principles and my knowledge of LED's to build something to my liking. this project is still going strong with no problems, no changing bulbs, no added heat. good luck with your project, theres much satisfaction of building it yourself. dont forget to post your results.

as to your last question, dont overdrive your LED's if there rated at 3.8 volts you should try to keep your supply close to that by using the appropiate resistors. which is always a good idea to use even a low ohm rating in series with your setup as it will resist any spike in voltage if your dc converter burns a winding and fails. this mainly can happen from drawing to much current from the adapter with the wrong setup. so its wise to have your dc converter with a ma rating of arounf 1/3 more than the draw. this is considered in the field to be optimum.

Has anyone tried using red/green/blue with a couple of yellows thrown in for good measure instead of just white?

dga: actually most of the threads die around the time SW is added That's the problem (in my books anyway). No real updates on how inverts like the lighting. I know from experience that plants thrive under LED lighting.

AfAqua: In theory you could use just red/blue to grow corals - there are many hydroponics systems now out with just red/blue lighting (Red's needed primarily for photosynthesis, the blue basically tells the plant in which direction to grow). But it wouldn't be very nice to look at. Blending colors to try to get a white balance is possible, but would require some serious computer controls to get it right. Meanwhile many of the current generation of LEDs have a very pleasing (to the reefer) coloring, mine are very close in output to a 14k (Depends on the manufacturer / bin - some are very crisp white - 6500-10000k some are much bluer like a 20,000k).

Andy

Man, you guys are a bunch of pessimists! My 5.5 has 6

Luxeon III stars providing the main light with a 13W actinic for the blue. The tricolor acro grew until it hit the glass and then started to grow on that. The weird little "tooth coral" from the LFS had only two open heads when I got it. Now there are around 20. The blastimosa is 4 times it's origional size. The xenia is out of control (I pull a couple of frags a week to trade with the LFS). The brown plate coral has grown 1/4" in a month all the way around. Things are growing better than those of friends using VHO's and halides.

I don't know if smaller LED's work well or not, but Luxeons kick ass. The light I am getting from the PC bulb is blue only, and could easily be replaced by Royal Blues and Cyans from Luxeon. It's not that they don't work, it's that it's freaking expensive to set up and requires a little circuit knowledge. They have dimmed not at all in 1yr. The claim is that in 100K hours, they will lose 50% of their output on average. So that's 27yrs, the way I run them. If they last 13, I'm happy.

On the "not enough light" front, let's do a little thinkin'. Most bulbs are round in cross section. Thus, half the light that is emitted is wasted. I know, we have reflectors, but these do not reflect all the light into the tank. Much restrikes the bulb. That is lost and heats the bulb, often resulting in less light output. Only the bottom 1/3 (at best) emitts light that goes into the tank directly. The LED's are highly directional. The Luxeon stars are 120 degree visible angle. With a lense (which just clips on, about $5 each), you can get 5,10,20,30,40, and 60 degree visible angles. So the 80 lumens they put out ALL go into the tank.

Some of these new high flux LED's are pushing 100 lumens per watt, as good as most halides, with no wasted light. As far as the spectrum goes, highly driven Luxeons of the proper bins are 10,000K. Mine are 6500K. It's all in what you want. I have not seen 20,000K's yet. they might never be made. It matters not at all to me; mine work very well. I must reiterate, though, they are expensive!

Okay, enough babble. Look up my tank in the gallery. I'll post some new pictures soon.

Kevin

dont forget luxeons get quite hot and must have a adequate heat sink. you will never see the 100,000 hours on a luxeon even at the rated voltage, there just not there yet with the technology. that rating falls to the 5mm (T 1-3/4) size drawing there rated voltage. its all about from which bin they come from as far as the whites. i have several versions of luxeons from 400ma to the 5 watt and all are different spectrums of white, mostly due to the phospherous. all of mine were from different bins. but for longevity, i will take a luxeon any day over a incandesant. all of my flashlights have been converted to luxeons. no more tungsten filiments for me.

Yeah, I should have mentioned that. Each Luxeon III is on it's own heat sink with fan. They are less than skin temp at all times (= feel cold), so less than 80F. I called Lumileds about the lifespan. As long as they are not being overdriven (less than 1A for the III's) and are kept below 80F, they claim that they will last the 100K hours. At higher temps, the lifespan goes down slowly until you hit around 100F. They claim (okay, taken with a grain of Oceanic sea salt) that the technology IS there. They have not been around the 27yrs, so they must be doing some modeling. Even at 50K hours, they pay for themselves in bulb replacements. And if you order from them, you can ask for a specific bin. The ones we want (more blue) are ones that most others don't.

They make great flashlight "bulbs", although the throw without optics is not great. Good tacticals, though.

Speaking of the technology, the new Luxeon I's due out in Aug. are supposed to be 60 lumens at 1.5W with a slightly longer lifespan. We'll see. They are working on a new V as well, hopefully with longer life.

There are others producing LEDs with more lumens/watt: Lighting Research Center has one producing 80lm/W and the new Dorado from Cotco is supposed to be 100lm/W. Given the geometry discussed above, that's the equivalent of 160-200lm/W of usable light (when using the spherical type bulbs as the standard). I think they've got it to the point at which it is a viable alternative to older style bulbs.

So why do you think the technology is not there yet? Nichia has a 1W out now, and their stuff has always been dead-on. they claim 100K hours, too.

if the info is coming from lumileds id take that as gospel for sure. ive never ordered from lumileds but from 3rd party techs that purchase from them. there are some optics for the luxeon i use in some of the flashlights with a 1 watt that rival a 2 d cell maglight.

a cyan luxeon 400ma badboy module with nx05 optics in a 2 AA cell minimag from 175 ft away

Daaaaamn! That's nice! Mine is one of the Dorcy head lamps. Bright, but no throw. Great for working in the tank with the hood to the side, though.

Okay, all you non-believers, here is the tank, running for about 1 year. Note the tricolor acro growing on the glass.

thats pretty sweet dude, looks bright as hell too. busy tank, i like it!

Thanks! I had to set the camera at ISO 200 to get a picture that was not a ball of light.