# DIY Cree XML LED Lighting for 150G



## Hoppy (Dec 24, 2005)

Those aluminum extrusions sure make a neat looking LED light. Beautiful job. Based on my data and on http://www.plantedtank.net/forums/diy/168999-one-way-design-planted-tank-led.html I think you get about 40 micromols of PAR at the substrate, with 3 inches of substrate in the tank. That is a great light level to use.


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## Wasserpest (Jun 12, 2003)

Yep, looks great. Do you know the total wattage (calc'd or measured) that this setup draws? Also, do you know your total cost?


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## fizzout (Jun 7, 2011)

Hoppy said:


> Those aluminum extrusions sure make a neat looking LED light. Beautiful job. Based on my data and on http://www.plantedtank.net/forums/diy/168999-one-way-design-planted-tank-led.html I think you get about 40 micromols of PAR at the substrate, with 3 inches of substrate in the tank. That is a great light level to use.


I am very happy with this heat sink. It turned out much neater than I even imagined. And thank you for doing the PAR calculations to confirm that I have about the right level of light. That was one area I was uncertain about. I am planning to simply have the lights slightly raised from the top of the tank, but I did consider getting optics to raise it higher (I think this may be better for getting access into the tank). This project has been very entertaining, so any additional work will probably add to that (I hope).


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## fizzout (Jun 7, 2011)

Wasserpest said:


> Yep, looks great. Do you know the total wattage (calc'd or measured) that this setup draws? Also, do you know your total cost?


Each LED should be about 8.75 watts (3.5V x 2.5A) resulting in about 70 watts for each string of 8 LEDs. I am only guessing on the forward voltage, but it should be close to actual. However, I am now curious enough to measure it tonight when I get home.

Edit #1: Total cost is less than $500 ($100 for drivers, $100 for aluminum, $200 for LEDs, then miscellaneous stuff like soldering iron)

Edit #2: I measured the voltages across several of the LEDs just now. It turns out that for the XML U2, the voltages are slightly above 3V, and for the XML T5, the voltages are slightly less than 3V. So using 3V as the average across all LEDs, each LED string uses 60 watts (3V x 2.5A x 8 LEDs). That gives me a total of 180 watts.


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## alexbn024 (Mar 27, 2012)

Hey fizzout,

That is one nice fixture! This might be a strange question, how do you adjust LED color to required temperature, say 6400K? Do you manually adjust voltage in the LED drive? Can you do it through Typhon controller? I am in the process of building my own mini LED fixture for my 20G (6x CREE XP-G R5 Cool White 3W over 12in heatsink) and I am trying to fill in blank spaces(and I have a lot of gaps on this subject)


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## fizzout (Jun 7, 2011)

alexbn024,
I have to admit that I did not build my lights with any particular color temperature in mind. However, I wanted something closer to cool white than anything warmer. That is why I decided to have a 2:1 ratios for CW to NW. However, the way the LEDs and the drivers are wired, I suppose I can put the CW and NW on separate dimmer channels to "balance" the color temperatures. But since I am happy with the current light color, I doubt that I will go to the added trouble. I did build another XPG light with a 1:1 ratio of CW to NW. I thought there would be a noticeable difference, but I honestly can't tell if it is any warmer than the XML. It looks fine over the plants (a little like sunlight).

From reading the many posts here, I concluded that 2:1 was close to what I would want. However, I think all CW would have been perfectly acceptable (and provide more light output). Having built the lights, the color temperature aspect does not seem crucial to me anymore. I hope this helps a little.


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## Doc7 (Apr 7, 2011)

Hello fizzout,

Looks great!

Did you do anything to seal solder connections from moisture? Notice you're pretty close to the tank.

I will use acrylic to protect mine from drips, but I am talking more about humidity. I know the reefers worry about corrosion quite a bit.


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## fizzout (Jun 7, 2011)

Hi, Doc.

Thanks for the complement. My original plan was to have the LEDs slightly raised above the glass cover of the tank. I assumed that the glass would be sufficient separation from the moisture and any drips (hopefully none). I didn't think the humidity would be a problem for the solder joints, but maybe that is something to consider (anyone know if this is a problem?). I know you can get a paint-on sealer for the solder joints but I did not go to that much trouble. I agree that reefers worry about the salt being corrosive to solder joints, but I did not believe freshwater posed such a risk.

In any case, I have decided couple weeks ago to hang the lights about one foot above the tank using 80-degree optics for better light penetration (and less light spillage outside the tank). From that height, I doubt I will need any additional barrier for water. Also, I like the clean and simple look of the lights as they are now, so I am hesitant to add anything else to it (other than the optics).

From what I have read so far, my lights will probably be fine as they are, but I am open to anyone's suggestions to improve my set up.

Good luck on your build.


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## Doc7 (Apr 7, 2011)

OK thanks for the info. I have had a lot of trouble finding this topic discussed on freshwater forums. My fixture will be several inches above the tank but within a partial (open-top) canopy if my current plan comes to fruition. Most likely a higher humidity area than "ambient" I think but still not quite sure if besides an acrylic sheet I will do anything to protect the LEDs. No glass top here.

Sent from my BlackBerry 9650 using Tapatalk


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## fizzout (Jun 7, 2011)

I would like to omit the glass top, but I want to keep the evaporation to a minimum. But even without a lid, I would not cover my LEDs as since they will be raised about one foot above the water surface. I don't think the humidity at that height will be as much of a problem, especially if there is air movement near the tank. Maybe someone can correct me. :icon_conf


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## fizzout (Jun 7, 2011)

So, I finally had time to install the optics on my CREE XML LED build. Unfortunately, the LEDs that I got from LightMalls did not fit perfectly with the optics that I got from LEDGroupBuy. I had to modify the optics so that they would fit flat on the LED star. I resorted to a crude method of creating cut-outs on one side of the optics with the soldering iron to match the location of where I soldered the wires to the LED star. It was not hard, but the result is less than pretty.

Anyhow, I wanted to warn everyone that optics for XML are not readily interchangeable. However, the XML LEDs from LEDGroupBuy fit perfectly with the optics, as they had opposite side soldering pads that matched the optics.

Here is a close up of the modified optics.








Here is the LED lights with all the optics installed. I'm making very slow progress, but progress none the less.








Let me know if there is a better way to modify the optics, as I may have another project using the same LEDs and optics.

Thanks.


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## byee (Apr 30, 2012)

Fizzout,

That's well thought out LED fixture you have built. 

I've considered building a LED setup for my 120 gallon reef tank but shy'd away from it due to costs. With my increasing hydro bills, I'm now reconsidering my options again. Anything to keep the expenses low!

I have some technical decisions questions about you LED build.

Why XML not the CREES or Bridgelux LED's?

Why the 2 to 1 ratio CW to NW? 

Do you know if the MW-90D-48 will work with your setup? How do you determine which MW LED driver is required for the setup?

Do you have plans to add royal blue LED's to your setup as atinics? 

Where did you purchase your extruded aluminum pieces from?

BTW, how are you liking you Typhoon? I've just finished reading the Typhoon thread on another site. Will be submitting an order for the PCB's in the next couple of days.

Looking forward to your reply!


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## fizzout (Jun 7, 2011)

byee said:


> Fizzout,
> 
> That's well thought out LED fixture you have built.
> ...
> Looking forward to your reply!


Thanks, byee. My decision to build my own LED lighting was partly due to the high electric bill. Also, I really wanted to build it because it seemed like a lot of fun, which it was. I'll try to answer your questions, but I only have experience with this build and another Cree XPG build, so hopefully, someone else will fill in any gaps.

_Why XML not the CREES or Bridgelux LED's?_
I decided to get the Cree XML LEDs because I read that they are the most efficient in terms of lumens per amp. Also, I' read that the Cree XML LEDs did not "wear out" like other LEDs because it didn't get as hot (hence the improvement in efficiency as well). Being that Cree has a good reputation, I was very impressed with the specs for the XML.

_Why the 2 to 1 ratio CW to NW? _
Now that the lights have been built, I wish I went with only CW LEDs. I thought that I needed the NW to provide a "fuller" spectrum for my plants, but the NW LEDs are less bright and they don't seem to really make too much of a difference visually. Hopefully someone will give us their insight on this.

_Do you know if the MW-90D-48 will work with your setup? How do you determine which MW LED driver is required for the setup?_
I'm not familiar with this driver, but I can tell you how I ended up with what I got. I needed to consider cost, current, voltage, efficiency, and dimming capability. Trying to get all these parameters right was not easy. I quickly found out that many of the drivers were simply not available or were long-lead items. Also, some of the drivers with the "best" fit were too expensive (~$100 each). Being impatient and cost conscious, I quickly narrowed my choices to what was available. Since I divided my LEDs into three separate strings, I decided that each string should have its own driver, which basically determined my current and voltage (~2 amps and 24 to 27 volts). I tried to get the best efficiency, but I really had no choice in this since there were very few options. So, the only thing left was the dimming capability and cost. That is how I ended up with ELN-60-27P (I used ELN-30-27P for my Cree XPG build). And the cost was acceptable too. These drivers are satisfactory, but these may not be the most "perfect" drivers.

_Where did you purchase your extruded aluminum pieces from?_
I got my aluminum pieces from Amazon. I listed the items I used below. This worked out well, but there is a wide selection of heat sinks.
80 25 SERIES 25-5013 50mm X 13mm T-SLOTTED EXTRUSION x 1220mm
80/20 10 SERIES 1010 1" X 1" T-SLOTTED EXTRUSION x 48"
80/20 10 Series 4265 2-HOLE SLOTTED CORNER BRACKET
80/20 Inc 10 Series 3321 Bolt Kit 1/4-20 X .687" FBHSCS And Economy Slide-In T-Nut

_BTW, how are you liking you Typhoon? I've just finished reading the Typhoon thread on another site. Will be submitting an order for the PCB's in the next couple of days._
I have not done too much with the Typhoon yet. Unfortunately, I shorted something on the board accidentally, so I need to replace it. :icon_frow
But it was working fine until I broke it. I was hoping to change the code to do multiple on/off cycles, but I had no time to play with it before I broke it.

Hopefully, I answered some of your questions to your satisfaction. Let me know if you have anything else you want to ask.

Thanks.


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## fizzout (Jun 7, 2011)

*Almost Finished Lights with Hanger*

It's been a while since I started this thread, but I'm at a point where I can say it is finished. I may add some aluminum "fins" to increase the heat dissipation capability, but that is a minor modification (I hope). The photo below shows LEDs and the hanger that is attached to the tank stand. You can find more information about the LED hanger in my tank journal thread.


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## Hoppy (Dec 24, 2005)

That hanger idea works great and looks great! Now, If you can just borrow a PAR meter and make sure you have the amount of light you want.


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## fizzout (Jun 7, 2011)

Hoppy said:


> That hanger idea works great and looks great! Now, If you can just borrow a PAR meter and make sure you have the amount of light you want.


Thanks, Hoppy. I would really love to measure the light level. With the reflected light off the glass cover, I wonder how much light is getting through. According to your formula, I think it is enough, but that does not account for the reflected light.


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## Pickled_Herring (Jul 26, 2010)

Best aquatic use of 80/20 ever! What kind of heat are you getting off the extrusions? I'm sure it's minor with that much aluminum. I use 80/20 at work and it's like working with a big erector set. It makes a very neat looking package. Nice Job!


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## fizzout (Jun 7, 2011)

Pickled_Herring said:


> Best aquatic use of 80/20 ever! What kind of heat are you getting off the extrusions? I'm sure it's minor with that much aluminum. I use 80/20 at work and it's like working with a big erector set. It makes a very neat looking package. Nice Job!


Thanks for the complement. I really do like these aluminum extrusions. They also have a very nice finish, which gives the lights a professional look. As for heat, the Cree XML LED do get warm running at 2.5 amps. But even without a fan, I can place my hand on the aluminum without it hurting. However, when I have a fan blowing on the lights, the aluminum is barely warm. I would definitely recommend a cooling fan to anyone planning on using these extrusions to extend the life of the LEDs. I will be adding "fins" to the XML LEDs to help along with the heat dissipation so that it doesn't get as warm. I'll make an update once the fins are installed.

In a previous post, I talked about having to replace one XML that went bad. I wonder if the LED adhesive had some air between the LED star and the aluminum to where the junction temperature exceeded specification. That would explain the problem. Maybe I should have used arctic alumina thermal adhesive instead of the double sided thermal adhesive tapes. :icon_neut


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## fizzout (Jun 7, 2011)

My "fins" arrived and I attached it to the LED heat sink using thermal adhesive. I'm not sure if it made too much of a difference, but I decided to continue to use a fan to keep cooling the LED so that they remain cool to the touch. Here is how the lights look now.


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## monkeyruler90 (Apr 13, 2008)

Looks amazing! I'm planning on building an led light with XML U2s and was wondering how hot they were going to get. Thanks for posing your experiences with them!!


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## fizzout (Jun 7, 2011)

monkeyruler90 said:


> Looks amazing! I'm planning on building an led light with XML U2s and was wondering how hot they were going to get. Thanks for posing your experiences with them!!


Thanks. I really enjoyed making this light. Everything fell into place very nicely. Ultimately, I don't think the LEDs are getting too hot (since I can touch the aluminum without discomfort when there is not fan). Still, the spec says that the LED will last indefinitely when kept at 30 deg Celsius so I'm using a fan across them. I don't know, I will probably replace these lights sooner than before the LEDs wear out. :hihi:


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## monkeyruler90 (Apr 13, 2008)

fizzout said:


> Anyhow, I wanted to warn everyone that optics for XML are not readily interchangeable. However, the XML LEDs from LEDGroupBuy fit perfectly with the optics, as they had opposite side soldering pads that matched the optics.


eek
so i received my LEDS from Rapidled.com and the optics from ledgroupbuy.com only to learn this lesson the hard way! The cut outs don't match the pads of the stars... guess i'm going to have to use the soldering iron to melt the plastic around the holes:frown:


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## fizzout (Jun 7, 2011)

monkeyruler90 said:


> eek
> so i received my LEDS from Rapidled.com and the optics from ledgroupbuy.com only to learn this lesson the hard way! The cut outs don't match the pads of the stars... guess i'm going to have to use the soldering iron to melt the plastic around the holes:frown:


I know how you feel. You might consider using a Drumel tool instead of the soldering iron, which was a little hard to control. I wish I had thought of that before. Make sure you leave enough of the double stick adhesive to stick on the star, though I didn't have any issue in that way.


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## jcgd (Feb 18, 2004)

I left the little holder part off and only installed the actual clear cone part of the lens. Works fine for me, just an idea. The white lens holder was a horrible fit. Between the start and my solder job, there wouldn't be much left by the time it would fit.


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## fizzout (Jun 7, 2011)

Really? I didn't even think that the lens could be taken out of the holder ... duh ... feeling stupid now.


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## jcgd (Feb 18, 2004)

Oh, maybe we have different ones. Mine came in two parts and you are supposed to snap them all together.


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## fizzout (Jun 7, 2011)

jcgd said:


> Oh, maybe we have different ones. Mine came in two parts and you are supposed to snap them all together.


I think you are right. I checked one of the spares and it's not obvious that it can be taken apart and used without the holder. Where did you get your lens?


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## monkeyruler90 (Apr 13, 2008)

Yeah I used the Dremel flat disk attachment to cut out a hole on the side. Fits pretty well now.

I wish LEDGroupBuy would say something about incompatibility with other stars


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## jcgd (Feb 18, 2004)

monkeyruler90 said:


> Yeah I used the Dremel flat disk attachment to cut out a hole on the side. Fits pretty well now.
> 
> I wish LEDGroupBuy would say something about incompatibility with other stars


I used only ledgroupbuy. And they were still incompatible!


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## fizzout (Jun 7, 2011)

*LED Driver Failed*

One of my Meanwell ELN-60-27P failed. I think it overheated. It looks like there is a small amount of current running to the LEDs, but the driver is fried. I ordered another power supplly (200w, 24v, 8.3A) to power all three banks of LEDs together. I gave up on the idea of dimmig the LEDs. I will adjust the height of the LEDs if I have to change the light intensity. At least for now, that is what I'm doing. Here is a shot of the LEDs with one of the banks lit very dimly.


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## fizzout (Jun 7, 2011)

Well, the other power supply finally showed up. I installed the new power supply and that showed that instead of the Meanwell driver having failed, it was one of the LEDs that failed. The Meanwell driver is working fine. I replaced the bad LED (which was easy to find), and the string now works. Since the Meanwell drivers are all working, I am not using the single power supply, which didn't actually work that well anyhow.


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## Wasserpest (Jun 12, 2003)

Arghh... can you send the power supply back? Do you think the dimming might have shortened the life of that LED?


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## fizzout (Jun 7, 2011)

Wasserpest said:


> Arghh... can you send the power supply back? Do you think the dimming might have shortened the life of that LED?


Yeah ... it was from China. Fortunately it was only $30. I guess you get what you pay for. I probably can use the power supply for something one day (I hope). As for the dimming, I wasn't using dimming, so I don't think it had anything to do with it. But I do wonder what caused the LED to fail.


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## bluediscus (Jul 31, 2009)

Hi fizzout, i know this is an old thread but do you have any updates of your build with the typhoon controller? I'm about to make a similar setup as yours and am wondering, are you able to dim your Meanwell ELN-60-27p completely?


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## skanderson (Jul 25, 2010)

any pics of how the lights look over the tank. i am interested in the color rendition of plants and fish with so much cool white led. there seems to be a movement away from the cree cool whites even in some reefer forums due to poor color rendition making things looks washed out. over my vivs i prefer the color of 2 to1 warm cool to the other way around. and i prefer the color of my 4k bridgelux to either of those combos. my new tank will have 4 k bridgelux with a bunch of lower wattage leds added for flexability in color and adder pop. also i love the aluminum 80/20. i used it on my viv led build and found it very easy to work with.


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