LED project... input appreciated

[ickypimp]

Hi, i have an 8-10 gallon cube tank that i want to nano. It is a nice looking tank , bow front with its own hood, the light , however is not so great, it has an 11 watt fluorescent tube, looking at various options and avalability and cost this is my latest thinking...

from what i have read i will need ~70 watts of light (a nonsense i know..)i was looking at a power compact bulb the other day (16 watts) that said that its output was 800 lumens

using that as a model 70/16 =4.3.. lets say 5 bulbs... this would be a squeeze in the hood and would generate some serious heat

If one compact fluorescent bulb gives off 800 lumens then 5 would give off 4000 lumens,

to convert lumens to MCD (measure of light emmited from an LED) you divide lumens by 12.57 then times by 1000

4000/12.57 = 318.2 x 1000 = 318,200 mcd

currently on ebay you can buy 60,000 mcd super white led's

318,200 / 60,000 = 5.3

is this so... i can get the same light from an led as a 16w compact fluorecent

the viewing angle of these things is ~12 degrees which means at ~30 cm(a foot depth) you get a spot around 8 cm in diameter, which will flood and dissapate to cover an area of around 12 cm

using πxR2 (π = 3.14) the area of light would be 113 cm2

the tank is 33x33 therefore its area is 1089 cm2

area of tank / area of light (1089/133)=9.6

Based upon these calculations i reckon that my nano could run with 10 of these LED's and get enough light to be equal to ~150 watts of more conventional lighting without all the heat

The spectral data from these leds indicates good levels of PAR avalable and plenty of blue light

I have 20 of these things so the light coild be boosted to the equivalent of 300 watts as i see it

any comments, suggestions or observations please would be apperciated

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[Anonymous]

>...convert lumens to MCD (measure of light emmited from an LED) you divide lumens by 12.57 then times by 1000

As you notice already, one issue with LED is the viewing angle. The narrow view angle of the LED is what makes the specs such a high mcd rating. It is very misleading when you do the conversion to compare how many LED you need to get the same light level as PC.

In another word, you need a lot more than 20 of these nice puppies to get the equiv. of 300 W of "conventional" lighting.

 

[ickypimp]

if you had read what i wrote properly you would see that i had also worked on the area of light due to angle and depth to come to my estimation of how many i would need, i think that i potentially have a very adiquate lighting system there that will give me "hot" and "cool" spots i think if i box clever with the fabrication of this i could have a system where light could be focused to the right areas

I get where you are coming from but you must see where i am at with the concept, i think that i can have asystem that offers focused areas of high intensuty light and moderat light in the rest of the tank

 

[Anonymous]

http://led.linear1.org/lumen.wiz

punching in the numbers, 60000 mcd, and 12 degree viewing angle, gives you the equivilant of 2.065 lumens. Granted I didn't read through all your math an explaination, but by going this method seems like you need 2000 leds to equal that 4000 lumens

 

[Anonymous]

LED light with 480,000 lux
http://cgi.ebay.com/GOLite-SAD-S-A-D-GO ... dZViewItem

 

[utahsaltreefer]

I built an array of 100 white leds and 50 blue leds. It was very nice over a 55 gallon. The white were 10000 mcd and the blue were 5500 mcd. It gave off a very nice color but in all honesty was only brighter than a NO light and not as bright as MH, PC, or VHO. The nice part was that it generated next to no heat. I have thought about ressurecting it for a nano though.

 

[Anonymous]

I built an array of 100 white leds and 50 blue leds. It was very nice over a 55 gallon. The white were 10000 mcd and the blue were 5500 mcd. It gave off a very nice color but in all honesty was only brighter than a NO light and not as bright as MH, PC, or VHO. The nice part was that it generated next to no heat. I have thought about ressurecting it for a nano though.

Do you have a picture of that anywhere? I would surely like to see it.

Thanks

Bryan

 

[Anonymous]

what do you want to do bry? I can help design/build it for you.

B

 

[Anonymous]

I'm not sure what I want to do, I have never seen a large array of those lights together, and was interested in what it looked like.

I am thinking about starting a really small tank on my desk, but its not going to be till next year and I am still looking for ideas.

No more upside down lighting schemes for me I think...

 

[Anonymous]

why even bother when all you need are 2-3 pc bulbs ?

 

[Anonymous]

There is some merit with LED. Heat and longivity of the bulbs, for example. However, as of now, it is still not an obvious winner when compare to other lighting alternative, particularly for larger systems. For nano, the advantage can be more noticeable.

 

[Anonymous]

not cost effective at all :wink:

 

[Anonymous]

not cost effective at all :wink:

The more my wife spends the less I care about cost effectiveness when it comes to my hobby....

:lol:

 

[Anonymous]

:lol:

 

[utahsaltreefer]

Sorry for the late reply. I don't have them all assembled anymore. I made a bunch of flashlights and lanterns for my kids to go camping with. I wired a few of the pieces back together and took some pics. Also it looks like something grimy drained onto them in the garage Anyway here they are. The big one has 42 lights and the smaller ones have 12 each. I made multiples so that I could angle them differently. The nice thing is that they all run off a single 12 volt transformer. LEDs may not be cost effective, but they are fun to play around with

 

[utahsaltreefer]

Last one

 

[Anonymous]

Ahhh


Now I get the idea

How come they are not cost effective? Don't they take way less power to run?

Of course talking about a very small tank


Thanks for sharing the pics...

 

[Anonymous]

The initial material cost outweight the saving in energy until you use it for 20 years or something like that.

 

[Anonymous]

Ahhh

So if I design a tank with a half life of 11 years I should use Led's right?

 

[Anonymous]

Well, if you want to use LED to replace four 1000Watt MHs, then you need to run it for a couple centries...

For small wattage tank, LED is good, not for large, bright tank until the price come down a bit more.