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Discussion Starter · #1 ·
LEDs are cute. Some are bright. Some get pretty hot. They direct light into (mainly) one direction. I like LEDs.

They used to be expensive. But they are coming down. Just found a website that offers 3W CREE LEDs for a very affordable price. Sure, they have trouble spelling, and you might get your merchandise in a few months because they are still collecting money to buy all those.

But it is going into the right direction.

Imagine a 1/2 inch tall canopy. Sexy.

Maybe 8 of them to light a 10gal tank. Hmmmm....

http://kaidomain.com/WEBUI/ProductDetail.aspx?TranID=1263
 

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Discussion Starter · #4 ·
Spypet, while the lamp you link to looks interesting, I doubt the LEDs have the punch needed for aquarium lighting. Imagine you have 100 1W Christmas tree bulbs, and compare them to one 100W bulb. I think it is the same thing with the regular cheap LEDs, joined in clusters, versus a few 3 Watt Luxeon or Cree bulbs. BIG difference.
 

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just for viewing there are led strips sold at walgreens that was really cheap but that was a x-mas closeout so I don't know if they still have it going.
 

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Wasser, do these Luxeon/Cree bulbs provide a broader spectrum of white light? I hesitated to pursue the LED bulbs I linked you to out of concern they were too strong on the Blue side of the light spectrum, as Red colors appear washed out under them.
 

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Spypet, while the lamp you link to looks interesting, I doubt the LEDs have the punch needed for aquarium lighting. Imagine you have 100 1W Christmas tree bulbs, and compare them to one 100W bulb. I think it is the same thing with the regular cheap LEDs, joined in clusters, versus a few 3 Watt Luxeon or Cree bulbs. BIG difference.
Thank you WASSERPEST!

I've been trying to convince people of that for some time. It's about intensity.

And 100 1 watt bulbs don't have the intensity of 1 100 watt bulb.
 

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The LED output seems as though it'll be very low, you need to think in lumens and the output just isn't there. Also, getting the light into the water is another story, an LED would need to be selected that directs its light very effeciently. I've no idea how well LEDs do at this.
 

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an LED would need to be selected that directs its light very effeciently. I've no idea how well LEDs do at this.
LEDs are actually spec'ed with an angle of light dispersion, such as 90° or 120°, so it's far easier to "direct" the light down into your water with an LED then with most other light sources, so with LEDs that have a narrow enough light dispersion rating, you don't even need a reflector.
 

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There is one company already manufacturing a LED aquarium light targeted for the reefing community. They often need higher light intensities for their corals, etc. Unfortunately, VERY pricey! And, of course, with actinic bulbs included.


Here is one very indepth review:

http://www.advancedaquarist.com/2006/8/review2

I think if I take the opportunity to read this three times I may actually begin to understand PAR and PUR!
 

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Discussion Starter · #12 ·
Got your math incorrect.

If you have 3 Watt LEDs, you don't need 111 of them. For a 10gal tank, I would count on 8 maybe.

Like I said, and Rex confirmed, there is a big difference between regular LEDs that you can find in cheap flashlights, coffee machine power indicators, and Christmas Tree lighting, versus 1, 3 or 5W Luxeon or Cree LEDs.

Yes there are LED fixtures for sale, yes they are crazy pricey, yes this is why I initially posted this -- to inspire DIYers with the ever falling price of multiple Watt LEDs.

I don't know about the spectrum of them, actually you can get burned by this too, they might have some tinge (I have seen slightly purple Luxeons). Can't say how plants will react to this, how the PAR compares, etc. Someone has got to invest $50 and make up one of those fixtures and just let the rest of the world know.
 

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Beg to differ, my Tek 216 watt fixture puts out 20,000 lumens. Each LED puts out 180. There is no substitute for light output, the plants aren't interested in how many watts are consumed.

My tank is 83 gallons, but that's really not relevant, it's a lumens per watt issue. The T5HOs are putting out 20000/216 = 90ish lumens per watt. The LEDs are putting out about 180/3 = 60 lumens per watt. I'm going to assume that they're using a far lower amperage, thus there is some economy associated with them.

There is room to debate whether an LED mixture has better PAR than the T5 starcoats that are popular in T5 systems. But even then you'll be within 30 or 40 percent (could be either way) of the 111 number, I'm certain you'd be in the range of 70 to 150 LEDs to match a common 4*65 CF or 4*54W T5HO fixture.

I think the LED solution will be most cost effective at the smaller/nano scale. The cost efficiencies of fluoro favour it on larger tank and push LED adoption to the lower sized tanks. I think you're correct on that. Although a straight numbers comparison doesn't make it look that good:

Larger Tank Options:

T5HO
4*54 watt Tek Light with four bulbs delivered to Canada = $450.00 +
20,000 lumens/$450 = 44 lumens per dollar + cost of new tubes

3 watt LED (assuming 111 LEDs @ $5 and $50 DIY electronics/fixture cost, this is a guess)
111*180 lumens/led = 20,000 lumens for $605 = 36 lumens per dollar


Smaller Tank Options (10 gal) - I know nothing about smaller tanks!
1 * FT36DL/835 (Dulux L) = $80 (guess from drsfostersmith)
2500 lumens/$80 = 31 lumens per dollar

3 Watt LED (assuming $25 for electronics/fixture cost)
14*180 lumens/led = 2500ish lumens for $105 = 23 lumens per dollar

I suppose zero maintenance and a cool factor could sell them... At the smaller end of the spectrum the difference isn't magnified as much.
 

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Discussion Starter · #14 ·
Beg to differ, my Tek 216 watt fixture puts out 20,000 lumens. Each LED puts out 180. There is no substitute for light output, the plants aren't interested in how many watts are consumed.
You have a good point there, but... it's also not just lumen that that plants are interested in. Lumen is measured as the light that radiates in all directions. While fluorescent bulbs have nice lumen numbers, much of that radiates into the fixture or onto the adjacent bulbs. Even with optimized reflectors.

With LEDs, the majority of the output is radiated into one direction, which results in a sad lumen measurement, but gets effectively more light to where you need it.

I agree that Watt is not a good measurement, but I also think Lumen is not a good measurement either. Now you get to candela and lux, and for hardcore lighters its PAR and such, and then we come in a big circle back to watts, for their simplicity.

Question is, when you compare a 13W PC bulb with 4 3W LEDs, do you get a similar, better or worse lit planted tank? Lumen-wise, the PC bulb wins, but like I said, I am not convinced it gets that much more light into your tank.

I agree that right now, using fluorescent bulbs is the smarter choice, but it is good to see that high wattage LEDs are coming down in price, right into the area where someone could buy a few and experiment on a spare 10gal tank.

It would be nice to come up with some electronic circuitry to slowly turn on/off these LEDs over the course of an hour.
 

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I wouldn't mind adding a few of those LED's to my Solar Oasis light bar and go totaly LED over that one tank I have. I've been waiting for a whitelight source that would brighten up the tank for the same cost as a PC bulb. With the LED bar I already have I bet 6 of these would do the trick.

If you want to know how effective LED's are at penetrating the water, look at moonlights, how far into the tank can you see with just a moonlight setup.
 

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Wasser, agreed that there's some question about how much light gets down. Best case with the fluoro's I'd guess is 85% or 90% with very good reflectors.

Incidentally in my searches for DIY LED systems I've seen that its possible to build dimmable LED systems which could have a whole host of purposes. Imagine a simulated solar and lunar cycle! Can you say breeding fish! I'm sure many species would love it, I think the reefers and breeders have begun messing with this, if anything it'd be very cool.

There is one problem and its sort of like fluoro systems in that certain ballasts and dim and others can't. And when you do dim you compromise bulb life. LED life is compromised by dimming and I'm sure different LEDs have different levels of damage, but the advertised life of the LEDs is in the order of 50,000 to 100,000 hrs(10 to 20 years @ 12 hrs per day) with 70% of the output remaining at end of life. So I'm thinking you could compromise the life a bit...
 

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With the sheer number of bulbs you are talking about in LED's, why dim? Set it into a controller that shuts off a percentage of the bulbs, no?
 

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Discussion Starter · #18 ·
With the sheer number of bulbs you are talking about in LED's, why dim? Set it into a controller that shuts off a percentage of the bulbs, no?
Not really... I suggested to start with 8 bulbs for a 10gal tank and go from there. Sure, you can turn off the front 4 or back 4 (assuming you arrange them 4x2), but as soon as you go down to 2 it will look funny, with a few bright spots in your tank.

Again... the cheap LEDs that are arranged in multi-bulb clusters are not bright enough to grow plants. They work well as moonlights though.

Also, a controller that turns off certain bulbs might be much more expensive than a voltage regulator... not sure though.
 

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I think Wasser's onto something in that even the more expensive LEDs are going to be in groups. Personally I'd conceptualized a group of banks that could be turned on and off, but it would depend on the economics of design on which way makes more sense.

You could even simulate the sunrise/set with some orange LEDs on one bank...
 

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Also, a controller that turns off certain bulbs might be much more expensive than a voltage regulator... not sure though.
I'd expect it to be the other way around. From an electrical engineering standpoint, I'd much rather build a system that shut off portions of the LEDs than a system that attempted to dim LEDs by regulating the voltage. The light output of an LED is nonlinear with a change in voltage, and if you go much above or below the standard operating voltage, you'll make a bunch of heat, which will cause the LED to draw more current, which will cause it to heat faster; left unchecked, an LED can blow itself up in <1 minute this way. Also, the circuitry for an adjustable DC voltage is far more complicated than the circuitry to turn something off.
 
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