DIY LED Lighting Fixture

[keno]

DoctaQ;

I welcome the input. I did not do any calculations to determine the number of LED's I would need. If there is a calculation that we can use to determine the number of LED's that would be needed that would be great.

If I follow your math, I have a 200 gallon that is 24 x 60. So the math would be 24*60/16 / 3 to get 30. I was thinking of putting 48 LED's for my 200 gallon. I will not be able to get exact spacing on the 200 gallon since I will be building two fixtures. My feeling is that the extra LED's will cover the gaps. Plus I will have the ability to dim if necessary. Additionally, if there are areas of the aquarium that are not as bright those areas can house the plants that need a lower light level.

I wonder if there needs to be a depth calculation in there also. For example when I was building the fixture for my 55 gallon, I took one of the heatsinks after I put the LED's and wiring on it and turned it on to test it. I then held the heatsink over my 20 gallon long aquarium. The six LED's did not seem like enough for this aquarium. My thoughts on that was due to the depth. The light cone does not have the depth to spread out.

 

[DoctaQ]

youve opened up quite the can of worms now
heres something to chew on in the meanwhile

http://www.nano-reef.com/forums/index.php?showtopic=192645&st=620

 

[DoctaQ]

based on that graph id guess 150ish par is all we need for high light plants, total guess though.
id bet that youd have 100ish par at 24 inches with 60 degree without overlap.

okay, looks like i totally overshot it, 100 par is already high light.
a long time ago i found par readings of a single led, and have been looking for it since. sadness, i will keep you posted

 

[keno]

This guy has some par measurements further down in his article...

Reef Central DIY LED lights

 

[DoctaQ]

yeap, his numbers look pretty low actually, seems kinda off to me, ive seen some fixture par readings as far as retrofits go but im hoping to get the par reading/spread of a single led maybe to come up with some kind of formula for number of leds based on height optics and the such

 

[CatsMeowww]

Ok, I am definately interested in these! Would something like this work?

http://www.heroledstore.com/15-mete...chip-smd-led-strip-channel-modules-p-459.html

I also found this one. For my 20 long, it might be an option.

http://www.heroledstore.com/22-inch-80-led-cool-white-fluorescent-t5-tube-500-lumen-5w18w-p-77.html

 

[DoctaQ]

cats, lumens are not the best measurement in terms of comparing light but kenos leds put out over 200 lumens each, the fixtures youre talking about are 500 total. you do the math.

there are drivers that let you put like 6-12 leds at 300 ma, and run off of ac current too, very easy to use and very cheap. im going to post it tonight when i get home.
for a total of 800-1200 lumens, and the kicker is that you can add the drivers up to get more power out of the same leds

 

[CatsMeowww]

Ahh. I think I am still missing part of the calculation process...I'll have to go over this thread again! I hate math.

 

[Nue]

Very Impressive Keno! Do leds have a kelvin rating?

 

[keno]

Nue;

Yes, the Cree XR-E Q5 Emitter I am using has a 10,000K maximum.