TOTW 12-3-08 DIY LED Hood for Reef Tank

[CharlotteSteve]

Removed-found One

[CharlotteSteve]

Got to test the first half of the tank today. From looking at the tank it will definantly need the other half of LEDs. Also the color isn't coming out quite how I invisioned, not sure if this is due to the lack of total light or the fact that these bulbs are only 5000k instead of the typ. 6-10,000k. On the bright side the light meter readings are more assuring.

I preformed three test on each at 18" away and the averages are below:

(1) 65w Coral Life 10,000k CFL = 1252 fc

(2) 65w Coral Life 10,000k CFL = 3237 fc

(12) Luxeon K2's = 1517 fc

This tells me that I am on par to compete with my 2 CFL's. I also have a 65w actinic in the current system, to replicate this I ordered 8 blue K2's. So the other 12 white and 8 blue's are coming in hopefully this week. I will be building two more heatsinks to accomodate the extra LED's. So with the new LED's we are at about 100V drop for everything!!!! but it's only at 1 amp so only 100w. Tell me what you think, it gets some getting used to. Something to note that may not have showed up in the pics, these things twinkle on the sand bed like halides!!!

[Lucid]

Your light tests look promising, especially when you get the other side hooked up. The blues should help out a lot too on the color. Got any pics of the LEDs?

Oh ya, I wonder what halides would come in at on the foot candles?

[CharlotteSteve]

Sorry don't really know where I can get a hold of a halide to test, maybe in a few weeks when I visit my brothers fish store. Wish I had taken a pic of the steup before I took it apart. I have to turn the LED's 90 deg. and add four more per side. However here are a few sketches.

[Zooman]

Would you list the materials you used? I am not a electrinics knowledged person and have no way of figuring it out. I want to work with LED to light my reef. Just can't without help.

[Mavvy]

Ok...noob here, where it comes to LED work. Steven, I'm also in Charlotte, and I too have a 37G; using a 250W MH and 2 65W actinics under the hood, I'm forced to stuff a chiller and pump (output split for flow) under the tank in the stand. I'd like something like you're presenting to decrease the need for all of that (I'd switch to Hydor Koralias and a wavemaker for flow in a New York minute).

Need a little info. I'm seeing you using 24 of the white and 8 of the actinic LEDs...is this correct, or have I miscounted? When all is said and done, what type of life should this be able to support (softies, stoneys, clams, etc.)? What do you show your final cost for materials to be? Will you present a wiring schematic? Perspiring minds...they wanna know. *LOL*

Thanks in advance, Obi-Wan.

[CharlotteSteve]

Ok, we did a little thinking and a little re-wiring and worked out all the kinks on how to run LEDs. The final setup will be 24 white and 8 blue. They will be on two heat sinks that are 5"x12"x2-1/2". The driver I found is CONSTANT CURRENT (absolute must!!) and has a pot to adjust the current from 4.5~9.5 amps with a maximum voltage of 15v or a max. Wattage of ~150w. I will set the LED's in an 8 parallel configuration with 4 LED's in series on each parallel. Then the driver will be adjusted to 7.5~8 amps depending on the temp. This will allow approx. .8~1 amp to flow through each set of LEDs.

The original design of two 2" angles back to back for a heat sink fell through when we ran the LEDs at close to full power. It got over 140 deg. f. So I ordered some heat sinks off eBay and with the calcs it should be more than enough.
Ok materials:
24 white Philips K2's (PW12)
8 royal blue Philips K2's (PR12)
32 bergquist K2 thermaclad stars
1 CONSTANT CURRENT driver 150w
Heat sinks to mount LEDs
Wire and solder and I would suggest getting a thermal couple meter to ensure accuracy.

I will be growing almost all softies/polyps except that Chile coral (that is a hard coral right?).

Final cost just over 600$. But I won't have to replace bulbs for 6+ years.

Wiring diagram is basic, I may add balancing resistors in the future but a little difference in light isn't going to be noticeable. Just 8 parallel circuits with 4 Leds in series on each. But really any configuration of Leds in parallel and series can be done as long as the LEDs aren't over driven with too much current and there is a sufficient amount of voltage. Another thing to keep in mind is the effect of a LED going out, an example: two parallel sets of 16 LEDs in series, one light goes out, now you doubled the current on the other leg because LED's will not consume current unless the circuit is completed. Doubling the current will almost certainly burn up some bulbs.

Everything is ready to roll, just waiting on a heat sink, again. I have pictures of the blues we added and the higher current btw this picture was taken with only 8 white LEDs and 4 blues. Will post when everything is setup

[sober_pollock]

Steve I have an electrical engineering degree from Purdue and I want you to know you have my respect and my compliments.

You have done very well on this.

One heads up i might give.....

That power supply you are using.....Surge protect it very well.....

I've been through about a half a dozen of those from different companies (All fundamentally the same) and it seems like when ever there is a lightning storm on the North American continent, I lose a power supply!

[Mavvy]

Now THAT'S what I'm talkin' about! Thanks!

[Parrothead]

tagging along with all the best

Robert

[CharlotteSteve]

Everything is hooked up and on top of the tank. This pic was taken after about three hours on the LEDs. I think it looks great. The Heatsink and Driver get very hot though around 125 deg f. I might put a fan on there or tell people to keep their paws off. The other concern is the amount of humidity between to water and the acrylic splash guard. So this morning I went to radio shack and bought two mini fans to force a little more air movement. I will keep you posted on growth!!! Final Led count 24 whites and 8 blues.

[CharlotteSteve]

Now that the fixture is completed I would like to toy with some controls. First I want to find a dimmer that is seperately powered from the LEDs. This is the only way that I can think of having a dimmer that ramps up to the ~3.6v needed for full brightness and then falling off at night until the dimmer reaches ~1-1.5v needed for moon lighting. I have thought of putting a capacitor in the system, but I would need to maintain a low voltage all night... Any ideas on how to accomplish this?

[rob_bozuk]

WOW...honestly..i just found my twin brother lol..i to just came back form my local fishstore..i was searching for a conversion from freshwater to saltwater in a 120 gallon tank..and i stumbled upon the SOLARIS unit..and the salesrep was just talking on and on about it..long time cost saving so on and so forth..EVERYTHING was true..except..BUT i can justify spending 4899.99 Canadian for something i can make myself..i have tonnes of experience with minor electrical work and i just couldnt bring myself to spending the money..i would rather try it myself..even if i fail..i would still do it..plus im a SUCKER for LED units..i already have a DIY for 50 intense blue LED for moonlight effect..
i didn't even finish the thread..as soon as i saw the first few sentences i knew where this was going..i HAD to sign up to post this reply..i too will be building this along side you (hopefully thats what you ended up doing..i couldn't get past the third sentence)..the temptation is killing me..gotta read on..
AHH THE POWER OF GOOGLE..

[quote=CharlotteSteve;185218]Finally after a few months of research and a LOT of questions I have finally reached the point in this project to begin buying material. I figured I wouldn't post until the boring part was over. Some background first. I am 21 and a mechanical engineer student at UNC Charlotte. I started in salt water 5 years ago. I have two 37g tanks piggybacked, one DT and a HUGE refuge (pics later). First off I have battled and argued for years about the best light for a reef tank. My conclusion PC's and VHO's are decent for softies but the bulbs are too........

[rob_bozuk]

heya im having the hardest time trying to locate a power supply..can you recommend anything? how about if i use a PC ATX power supply? which i dont want to..id rather have amperage control like you mentioned..ANY help would be appreciated

[CharlotteSteve]

The PC power supplies have a "dirty" signal, meaning the current fluctuates and is bad for LED's. So the first criteria for a power supply must be constant current, if it isn't constant current I wouldn't bother with it. You can use a dirty power supply but you will have to buy "Buck-Puck”‘s for each set of three LED's (they only are rated for 12V/1Amp) which is going to be more $$$ and a crappier end product. I found my power supply at onlinecomponents.com . It's the Meanwell CLG-150C. The great thing about this power supply is that it has Current and Voltage Pots built in. I say this is good because I can change the configuration or add/subtract LEDs without buying a new power supply. This power supply is 150w so it can handle up to like 40-50 high output LEDs.

The other thing to really consider before starting, I wish I did, is the Heat given off by the power supply and the LED's. The power supply will not over heat or burn up, but you will defiantly want to keep it away from anyone. It isn't so hot that it will cause a mark, but it will get your attention. Also the slug on the back side of the LED's gets really hot. Even with that huge Heat sink on my setup, it still gets up to 120 deg F.

I am more than pleased with this setup, I have turned into Billy Mayes over night, I'm sure my roommates are about to kill me. The coral seem to be growing every day. I have enough light to put the elegant coral on the bottom where it's natural. I also read a little bit on the internet about how fluorescents look brighter to the human eye because of the presence of the red spectrum in the light. In this case the specs call for a very small amount of red spectrum in the LEDs, so even if they appear just as bright as the CFL's, they're actually putting out more light.

[rob_bozuk]

Hey there...sorry to keep asking but I want to get everything down to the last dot...
I did some thinking and this is what I figured out…because my tank would be different then yours in size...I would have to make a few changes to your setup...firstly I would need to make a 60 inch design because my tank is a 110 gallon…I would need more LED’s per heatsink then you to get a wider surface light emitting area….

This is my design…aerial view of the tank and position of heatsinks...
and the diagrams to size...



4 - 9”X9” heat sinks…
100 – LED’s (haven’t decided on the blue to white ratio of led colours)
2 – PSU’s (I just had 1 question about that…you bought the 12 volt model I’m assuming because you wouldn’t need anything more powerful then that to power these bad boys)

AND ALSO...(32 bergquist K2 thermaclad stars) I cant find an image of these things…is they’re any way you can direct me to an image so I know what your talking about here..? from what you said quantity number wise...the LED’s mount onto these...but I just cant figure out how..

USUALLY I just jump into a project and just get dirty...BUT...we are talking about a large project here (money)…
With my calculations I would be WELL over the thousand dollar mark…So its kind of important to get every last detail down…

[CharlotteSteve]

I bought a model that would go up to 18v because I ran 8 sets of 4 series LEDs in Parallel, which would give me a voltage drop of 3.5v*4=14V. The LEDs will only drop a certain amount of voltage so don't worry about throwing too much v at them.
No picture, there is a PDF of the datasheet with a diagram, go to digikey.com and search for 803126. Make sure you get this one and that it matches the datasheet, digikey has been known to have misleading descriptions, but the part numbers are always right.
Digikey is also the only place I have found them. The idea behind these boards is to separate the thermal conductivity from the electric conductivity thru layers of substrate.

About choosing LEDs, I feel confident that 2 white LEDs to every blue is the ticket. Whether you mix up the Royal Blue, Blue and Cyan is your call. You really can't go wrong because all these LEDs look great. I can back this up because of the few companys that sell LED fixtures use this same pattern (just google their patents).

[rob_bozuk]

wow i forgot to take voltage drop into play here..

Ok..they only have the 20 volt model next to the 15 volt model..so I'm planning on running...
50 LED's each PSU..
150 WATT per PSU...
3.5V x 5 = 17.5V so the 20V should be sufficient enough...

JUST want to confirm this also with you..series setup..because i usually run my setups in parallel or one LED to a PSU or battery...


using your setup instead of running 4 in series i will be running 5 per series

And i didn't want to draw everything out in the picture but i would have 10 sets of this running out of one PSU..So it would be 2 main wires coming out of the PSU which branch into 10 sets of 5 LED's running in series...

(im sure thats correct)


I spoke to a gentlemen whose selling me a GIANT heatsink..
3/4" width x 27-3/16" length x 1-5/8" height

I also spoke to my cousin who has a shop and he said he could cut the aluminum heatsink to whatever size i required..

everything is piecing together..slowly..ill start up my own thread when i get this running and ill have an instructable also..

BUT before i get ahead of myself..ill be on you like crap stuck to Velcro..Just a couple more questions left..i SWEAR...

OHH SIDE NOTE...And I had taken a look at the setup of the Solaris and all there setups are the same for every model but they just add an extra grid for the larger lengths..



there grid is a 5 by 5 and there colours alternate...and if you count it off..they use more blues then whites..but when you actually see there setups in person..you do notice that the water is richer in blue then it is with the white..but again..its pure trial and error at this point...

[CharlotteSteve]

Yep, I'm assuming you'll be using the K2's which can run 700mA~1A. Ten sets gives you 7A~10A. The power supply is only good for 7.5A, so you will be running these on the lower end, which is okay esp. for thermals. Don't forget to do a few calculations and test to monitor your thermals the first few times. There is a fun long equation with many variables for the convection of the Heatsink. However I found the easiest way was to fire them up and let them get to a steady temp then take the ratio of that temp and where you want the temp to be. Since you can't change the material or the ambient temp, the only thing that you can change is the surface area. Oh and if you wanted to run the LEDs harder just take a leg off the parellel, probably the same light output though. Yeah I'm not crazy about how the solaris looks, I know thats how most corals really look at depth, but I like more white, just a personal pref. Plus they're LEDs can be individually controlled so it's not a big deal to balance the white and blue. In our situation since we don't have fancy computers the colors have to be pre-set.

[CharlotteSteve]

After a few weeks the lights still look great and my tank hasn't freaked out. In fact i am seeing a lot more growth and I have been able to move some of the corals lower in the column. However I have noticed two things that are troubling. The corals towards the end of the day (7-8 pm) seem to retract, which they didn't do when I had the PC's and I am seeing a slight increase in cyana, which I had almost none before. My theory is that the corals are getting more light and therefore require a shorter photo-cycle, maybe the cyana is getting too much light also. I cut the timer back a little to see if this helps. Hopefully my tank just needs time to settle in to the new light and can handle the bacteria flair.