LED and other light sources

[studiot]

The last thread on light sources was in politics

 

John Cutherber

Just a thought.

Would you like to start a different thread for a discussion of LEDs (etc) and aquaria?

 

So here's a start for a technical thread.

[Moontanman]

ideally a light source for a marine Reef aquarium should imitate north light

 

Coral zooxanthellae light absorption

 

http://www.advancedaquarist.com/2002/2/aafeature_album/Image1.gif/image_preview

Edited July 14, 2012 by Moontanman

[studiot]

Well here are photos of my LED unit.

 

The delta suppressor does not work - it's really for mains borne interference.

The lamp totally wipes out AM and FM radio within about a 7metre radius. Not good.

 

I also had recent experience of some 24 volt recessed ceiling units in the barge.

They were supposedly replacement fittings for low energy units but the light output is disappointing.

I think the source is too far up inside the can, remembering how intense it is because of its small size.

So the light can't get out so easily.

[Moontanman]

I think it's interesting that what is supposed to be such an efficient light gives off so much waste heat?

 

ideally a light source for a marine Reef aquarium should imitate north light

 

Coral zooxanthellae light absorption

 

http://www.advancedaquarist.com/2002/2/aafeature_album/Image1.gif/image_preview

 

 

Try this link...

 

http://www.advancedaquarist.com/2002/2/aafeature/

[JMJones0424]

I think it's interesting that what is supposed to be such an efficient light gives off so much waste heat?

LEDs are more efficient, in that they produce more lumens per watt, however they emit almost no infrared radiation. An HID metal halide will radiate away a tremendous amount of waste heat through infrared, but a comparable LED can only shed that heat through conduction into massive heat sinks. Poorly designed heat sinks are notorious for reducing the lifespan of LED assemblies.

[Moontanman]

LEDs are more efficient, in that they produce more lumens per watt, however they emit almost no infrared radiation. An HID metal halide will radiate away a tremendous amount of waste heat through infrared, but a comparable LED can only shed that heat through conduction into massive heat sinks. Poorly designed heat sinks are notorious for reducing the lifespan of LED assemblies.

 

 

I have the feeling LEDs are not yet really suitable for marine reef tanks, the spectrum is just not there or the intensity...

[studiot]

Poorly designed heat sinks are notorious for reducing the lifespan of LED assemblies.

 

And starting fires.

[AbeMichelson]

There are some ultrabright LEDs on the market (Luxeon Rebel) that are pretty bright. Why not Halogen lamps (I know they produce tons of heat waste, but they are better at mimicking the sun)? It looks like the peaks in the plankton response do not match up to the peaks in the LED spectra. I doubt it would be a major problem, but it's something to think about.

 

A neat idea for an aquarium would be to use water cooling in lieu of heat sinks since you have all of the major components.

[Moontanman]

There are some ultrabright LEDs on the market (Luxeon Rebel) that are pretty bright. Why not Halogen lamps (I know they produce tons of heat waste, but they are better at mimicking the sun)? It looks like the peaks in the plankton response do not match up to the peaks in the LED spectra. I doubt it would be a major problem, but it's something to think about.

 

A neat idea for an aquarium would be to use water cooling in lieu of heat sinks since you have all of the major components.

 

 

There are "now" LED's on the market specifically made for aquariums that grow coral and plants like nothing else and using the aquarium water for cooling would be a disaster, cooked fish don't swim well...

Edited January 8, 2014 by Moontanman