sphearion Posted June 13, 2004 Share Posted June 13, 2004 ok, I called my local lighting guy that was working on a dual 150watt MH / 2 VHO Flouro hood for me - was cheaper to have him make it then just to order the parts and make it myself Anyway during the course of our discussion he mentioned 10,000K LEDS he said a strip was $24.00 and I know that LEDS don't put off a whole lot of heat, as well as not really a lot of light. what I was wondering is by your best guestimate how many leds would it take to light a 30gal *I found out that blue leds are on the 450nm range of light *ACTINIC?* so I could make strips of 50/50 and have 50/50 lighting that uses very little electricity, low heat, but im worried about the amount I would need?!?! anyway any replys are appreciated Link to comment
Rikko Posted June 14, 2004 Share Posted June 14, 2004 LEDs actually put out a TON of light. I was doing a little math the other night, maybe someone can correct me. The different coloured LEDs have different light output levels. A typical true white LED at the recommended voltage (you can overclock them for more light, but you reduce their life somewhat - I think a little overclocking is always in order! ) will put out 8000mcd - that's 8 candles, which is 8 lumens. They can go up to 10 lumens safely if my source (www.besthongkong.com - also a great and cheap place to mail order them) is correct. Each LED is about 5mm wide, so let's take a T5 fluorescent as our example. If you line up 3 LEDs it's roughly the same width as a T5 tube. Now run them in a line.. I have data for 6400K full spectrum T5s right here, so that's what I'm using. I run these bulbs on my FW tank and they are extremely bright (though I wouldn't use them alone to keep clams). A 4' tube draws 28W and produces 2750 lumens. Let's say we line up rows of 3 LEDs (you could probably make a case for using 4 or 5 since the bulb will need some clearance). Each 5mm of "length" is putting out about 25 lumens. 1" = 2.54cm = 25.4mm. 4'X25.4mm = 1.22m. 1.22m/5mm ~= 250 rows of LEDs. Now 250 * 25 = 6250 lumens! (Hmm. The last time I did that in my head I didn't get such a favourable result.. Someone find my error?) And, on top of that, the LEDs at normal output draw 3V@15mA. One LED draws, then, 0.045W. If we have 750 LEDs, that's a draw of 33.75W! That wasn't even my point, though I'm delighted by what my math said. I'll do it again later on paper. My point (stolen from another friend) is that LED light is a point source, so there is essentially NO wasted light (minus a wee bit from the sides and rear). With any sort of tubes you have reflectors which reflect "99.9%", but take into account all the light bouncing off the surface of the water, from the reflector back into the light, etc. It's very doable and a worthy experiment - there's a thread or two on reefcentral where a few guys have already done quite a bit and I've been watching the thread closely (See "LED as main light?" in the Lighting forum). Myself I'm still getting things together but I'm going to build a strip using the blue, UV, white, and perhaps another colour of LED and see what happens with a few softies and SPS. I'll report back in a few months with some results. Link to comment
sphearion Posted June 17, 2004 Author Share Posted June 17, 2004 Thank you very much, my biggest concern is that they are a point light source, I mean on a 10gal tank now many Leds would you need to keep clams! j/k you would probably need far far tooo many! Link to comment
xcajx Posted June 18, 2004 Share Posted June 18, 2004 keep us posted, they would be easy as hell to set up with a little solder and a simple bracket - like an old ruler even. I have done this with blues for a moonlight. Not hard at all. I do not know my lighting very well. How many K is the 8000mcd@20mA ? Link to comment
LEDSUPPLY Posted June 18, 2004 Share Posted June 18, 2004 Hey all, I was checking where people were referred our site from and your site came up so I decided to check it out. Large advancements have been made recently in LED technology. There are also alternatives to regular 5mm LEDs. Luxeon makes a product that is as bright as 25-30 5mm LEDs. Granted LEDs are a point light source but with optics can be made to be a general light source. I'd like to thank you for your references to our site, and don't forget for all of your LED lighting needs visit us from LED Supply at www.ledsupply.com. Best Regards, LED Supply Staff Link to comment
Gomer Posted June 20, 2004 Share Posted June 20, 2004 I think you need to see my LED setups I have 4 different LED lights built http://www.aquaticplantcentral.com/forum/v...opic.php?t=1068 Link to comment
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