LED light?

emlafn

Registered Member
Dec 15, 2005
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How much LED wattage is needed to roughly equal 20 watts of CF light? Does it work for planted aquariums?
 
i'm not too sure of the LED equivelant to 20W incandescent (LED's come in various light output levels) but as far as I know LED's do not give appropriate light for plants.
 
right, when I think LED lights for aquaria, I imagine blue moonlights or other night-viewing lights. See this thread http://www.thekrib.com/Lights/led.html

Gathered from that, I'd agree with C_130_Herc that LED is not ideal for planted tanks. According to the link, the technology is not quite there yet. The last post on that site is from Tom Barr, our very own "plantbrain". He's an absolute plant guru and definitely knows his stuff. It seems he only thinks of LED's as moonlights, too.
 
LEDs are measured in watts just like any other bulb, but they give a much more intense light than CF (watt per watt) IMO. They are making 7 and higher watt LED's that are insanely bright. I doubt if they can support plant life, but they can certainly light a tank with some cool effects.
 
http://www.solarisled.com/

Apparently somebody thinks that it's possible to get enough light intensity for a reef tank, I would imagine that the same principle could be used for a planted aquaria.

if you could control the spectrum of the light, it would definately be possible.

you should be able to use enough of any kind of light source to get the equivalent of a 20w CF bulb, the question would be efficiency and/or cost. you could use a bunch of flashlights to get the same amount of light, but it wouldn't necessarily be feasible.
 
I think LED's (at the current technology) would take a lot of tweaking. there's a lot of other high output lights that are great for planted tanks. For instance, T-5 High Output, VHO (Very High Output), Compact Flourescent, Power Compact
 
emlafn said:
So in general they aren't suited for planted tanks?

Well I have yet to hear anyone using led lighting for any other than moonlighting so yeah I would say generaly they arent suited for a plant tank. I'd be curious to hear more about the product in that link though. Usually LED's seem pretty bright because they are very narrow spectrum and also narrow veiwing angle, much like how a 5mW laser diode can be much brighter than what you would normally expect from a 0.005W light. I suppose it is possible though if you provide light with similar peaks in the red and blue spectrum it should work, I amagine more and more testing will be done in the future with led lighting but for right now I havent seen very much conclusive reports on led lighting.

Also LEDs are usually rated in millicandelas (mcd). Wattage really doesnt apply since wattage is not light - its the electrical power consumed, and the lumen per watt of an LED is going to be very different than that of a flourescent bulb (I assume anyhow). To get the lumen output of an LED you need to know the mcd rating an the 'viewing angle' of the LED since most of the light is only projected within a certain angle. There is a handy calculator here that will calculate how many lumens a LED will produce: http://led.linear1.org/lumen.wiz And just for example a typical ultra-bright LED rated at 10,000mcd and 20* angle produces 1 lumen. Most shoplights bulbs produce around 3,000 lumens.
 
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Yes, LEDs can grow plants. There's company that sells an array for house plants instead of using high pressure sodium bulbs.

They do put out a color spectrum that is appropriate for palnts.

However, a light with the right kind of LEDs, would be monstrous. While it's cheap to put a few in a flash light, or to use as moon lights, it's entirely too expensive to build a large enogh array to use for tank lighting in which you want that tank to be planted.

It would take years upon years to recoup the savings in power, and bulb changes.

Dansdata.com had an article on them a few months back.
 
I dunno about all LEDs but the ones used for fiber optic communications only have a spectral output that is like 40-80nanometers wide. Meaning basically they are only 1 color. I think you'd have to have a wide assortment of different ones to get a full spectrum.
 
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