DIY LEDs - The write-up

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getting ready to start assembly on my 75's LED hood. i went with 36 LEDs per side (18 blue/18 white). all will be driven by 12 buckpucks (6x 1000mA and 6x 700mA). so i know that they can be dimmed via 5k pots and will probably go this route at first, but want to get into a microcontroller like the Arduino eventually. has anyone done this yet? ive seen numerous sites where people are attempting it, and some accomplishing it via the PWM output - but theyre driving the buckpuck control pin directly from the Arduino - thats not appropriate for 12 buckpucks, though. ive seen schematics where folks recommend 1 transistor per buckpuck, and schematics that have a whole chain of buckpucks wired to 1 transistor. whats the consensus here?
 
Anyone find a cheap place for thermal tape? I'm going to redo my LED fixture to have 2/3 royal blue and 1/3 cool white.
 
<a href=showthread.php?s=&postid=15454552#post15454552 target=_blank>Originally posted</a> by sammy113
Anyone ever tried this LEDs? I know they are not CREE or any recognized brand. Any idea if they are worth something? They're very cheap tough. I might try it just for fun

http://cgi.ebay.com/5x-White-High-P...in_0?hash=item35a2b2ab8e&_trksid=p3911.c0.m14

Yea, I have. They work. Not the best tho. Just not enoulf light. Now if it is not putting out 400lm or better I just won't bother. You will still need the same ammounts of pucks / drivers you get alot less lights. I used on an 11" heatsink. 24 of them didnt match the 12 rebels on the other heatsink. so on an 11" heat sink (using a light meter) it took 41 to equal the 180 lumes at 30"
Grue
 
<a href=showthread.php?s=&postid=15456103#post15456103 target=_blank>Originally posted</a> by Grue
Yea, I have. They work. Not the best tho. Just not enoulf light. Now if it is not putting out 400lm or better I just won't bother. You will still need the same ammounts of pucks / drivers you get alot less lights. I used on an 11" heatsink. 24 of them didnt match the 12 rebels on the other heatsink. so on an 11" heat sink (using a light meter) it took 41 to equal the 180 lumes at 30"
Grue

Thanks for your aswer. Since I'm thinking of this for a very small tank, maybe it could work. Is for keeping zoas and shrooms so they don't need a lot of light.
 
Keep in mind though that, in the end, it's an efficiency tradeoff.

Let's say you have a LED, model A, that makes 45 lumens/watt, and another, model B, that makes 90 lumens/watt.

Now, let's say you need 900 lumens if light. That's 20 model A, or 10 model B. If model A is $3 each, and model B is $5 each, it's more economical to buy 10 model B's than 20 model A's. And, besides the cost of the LED, you have to consider the cost to drive the LED, which for most fixtures will be a significant percentage of the overall price. In other words, to buy power supplies, drivers, controllers, etc. for 20 model A's will be twice as expensive as 10 model B's, so again it makes more sense to buy a smaller number of the better LED, even though they seem more expensive.

So, even if you don't think you need a ton of light, it still might be "better" to get a smaller number of really good LEDs than a whole bunch of unknown cheap ones.

Plus, since the make, model, and bin of those eBay LEDs is not specified, I would put absolutely zero trust in the specs they publish. Or, even in the fact that you'll get the same part each time you order. For all we know, they're just selling junk parts from wherever they can get them.
 
If I wanted to do LED's over a 44x24x22 tank how many would I need and want type. I think I would go 50/50 white and blue. Help me with this. Buck Pucks or MeanWell, I really don't know the difference. Sounds like the MeanWell eliminates the need for Buck Pucks whatever they are.
 
meanwells are a combination of the buckpuck (the led driver that converts the ac input into a dc current to power the led) + a 110v power source. the meanwells will run up to about 12 leds & the buckpucks about 6.

meanwell makes dimmable units but at the moment are all but unobtainable, so if you want to dim the leds to match a color spectrum &/or overall intensity, the buckpucks are the way to go
 
<a href=showthread.php?s=&postid=15460744#post15460744 target=_blank>Originally posted</a> by JTL
If I wanted to do LED's over a 44x24x22 tank how many would I need and want type. I think I would go 50/50 white and blue. Help me with this. Buck Pucks or MeanWell, I really don't know the difference. Sounds like the MeanWell eliminates the need for Buck Pucks whatever they are.

are you going to be using lenses? If so, what angle? What gallon tank would those dimensions be for?
 
I would only use the lenses if it were necessary. The tank is about 90 gal. I thought that maybe I could get by with 36 white and 36 blue.
 
Unfortunately, that is the big question. I am new to this but I don't plan on getting into anything that is extremely difficult to keep. I am trying to plan ahead but that isn't so easy. My thought is soft of which i have a few frags and mushrooms and in my new tank some lps.
John
 
I think 72 should be fine without optics for softies, you can always add on optics later if you want to increase the intensity. Although I don't think you'll be able to cover the whole tank. A couple of inches on either side and front to back uncovered will not be a big deal.

50/50 will give you a 10K look. That is what I have at the moment. I want mine bluer, so I'm going to change it to 2/3 RB and 1/3 CW. I have dimmers, but I don't want to turn the white down, since I have SPS near the bottom.

edit: In general, if your LEDs are two inches apart, use 60 degree optics to achieve 150W MH power, and 40 optics if you want 250W MH intensity.
 
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Okay. I've spent many hours reading nearly every post in this epic thread. There are a lot of great examples and a lot of questions... I'm hoping to have one more question answered.

I'm in the planning stages of a 40 breeder (my first ever SW tank). I'm looking at Soundwave's initial setup for the majority of my inspiration here. My dimensions are 36x18x17 and I pla n on not using optics. It seems that the majority of builders here are having too much light more often than not enough, so I don't plan on using optics. I plan on having 36 LEDS total, half and half. I'll most likely be using the CREE XRE stars as they seem to have the most user interaction on the boards so far (less to be surprised about).

I'd prefer MeanWells as they are by default dimmable but I see in a recent post that they may be hard to come by. I also like the fact that I would only need three as opposed to six drivers. Either way I will be dimming them (or at least retaining the option to do so). I'll figure out a power supply down the road, I'm not in a huge hurry for this.

I plan on arranging my LEDs in 3 rows of 12 (unless you think there's a better way). i figure the three rows will be spaced roughly three inches apart and the 12 columns either 2 or 2.5 inches apart. Arranged in a checkerboard pattern like pretty much everyone else.

One dimmer will control the center row entirely (blue and white). One will control white for the outside rows and the final will control blue for the outside rows. Down the road I'd love to work up a servo timer to auto rotate the dimming knobs to provide a truly seamless morning and evening spectrum. I've got no experience with that, however, so it's a pipe dream at this point.

I'd like to tap them into the heatsink (probably use heatsinkusa) but will thermal glue if I need to. The fixture will be cooled with CPU fans and housed in a wooden canopy that I'll build myself.

Unless I can find a sweet deal, I'm guessing it will run me at least 350. I plan on building this over the course of the next many months as I still need to buy a skimmer and build my stand/canopy/sump.

Since I'm new to the SW game I'm not looking to create a SPS garden here, but I'd love to be able to keep softies (frogspawn, zoas, shrooms etc) and maybe a clam (too high light demanding perhaps?).

How does the idea in theory sound? Would 24 LEDs work or is that really pushing it? I figure if Soundwave lit a 75 with 48 LEDs and no optics, I might be able to do half the volume with half the light. It would certainly speed up my production rate if I could cut 12 LEDs off of this project.
 
LED light setup

LED light setup

I'm running 12 blue 12 whites on a 29 gal tank and it turned out to be too much light as compared to the 150mh I had with an old bulb. I think your design would work just fine. PS: I have a 12" derasa in the tank that is doing just fine.
 
The 29 is the same vertical depth right? Just not as big of a footprint? I may just do the 24 if that's the case... Btw what is that coral you mentioned? Is it an sps?
 
Lighting has come a long way, I am glad I have spent so much time researching before buying. I have just purchased a 220 gallon (72 x 24 x 30h) that I plan to make into a reef tank. I would like the option of clams and sps on the sand. I would like the ability to dim everything on a few different circuits, and plan to do so with an Apex. I have spent way to much time reading this thread but I think I have a setup planed.

I plan to have 7 rows front to back with 26 LED's each row, spacing will be 3" front to back and 2.5" left to right, a total of 182! I will alternate between White http://www.dealextreme.com/details.dx/sku.2394 and Royal Blue http://www.ledsupply.com/creexre-rb.php 1:1. I want to use the Meanwell ELN-60-48D driver if I can find them, with 13 LED's on each. All of the LED's will be mounted on heatsinks with fans to cool them.

Now for my questions:

1. I think I will need some optics to go with these but I don't know which ones, or where to buy.
2. Where can I find the Royal Blue LED's at a better price?
3. I can afford to wait for the Meanwells so where can I get the best price?
4. Will this setup work as I hope?
 
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