# LETs LED !



## Christos Ioannou (25 Apr 2016)

Hi ukaps,

inspired by this thread (thanks @SuperColey1 for sharing!), I have replaced my twin 54w T5 fixture with this:







The construction is exactly the same as that in the inspiration thread, except for the supports, since I have opted to hang the fixture from the ceiling with 1,5mm wire rope.

Having had the inspiration, I stumbled across this bundle at what I think a very reasonable price, including free fast courier shipping!
The bundle includes 30 3w LEDs on star heatsinks, 3 drivers (10 leds on each driver), 1 controller, 30 lenses and wiring. I picked up the 120 degree lenses.

*This is what the package includes*
Seller was VERY helpful and fast to answer any questions I had.



Looking at off the shelf proven LEDs, I could see that leading manufacturers included colored LEDs along with white ones. So, I modified my order as follows:
1. 6000k-6500k 3W LEDs [x24]
2. royal blue 440nm-460nm 3W LEDs [x3]
3. Red  630nm 3W LEDS [x3]

A problem I had to overcome was that of a heat sink. For me, one of the principles of DIY is to keep costs low . Given that I wanted this fixture to cover an 140cm long tank, it was very difficult to source a continuous length of heat sink, without breaking the bank (including shipping!)

I searched around reef forums (reefers seem to be doing a lot of DIY work for LED lights) to see that they are using U channel aluminum profiles to mount their LEDS on. But, I was also going for looks, so a bold U profile was not fitting the bill... So I was off to the shops, where I could get 7.5mm U channels that were later epoxy glued together into ...heat sinks!
Cost of aluminum: 20eur
Cost of epoxy: 5eur

*Result*
3 heat sinks each 122cm long; 3cm wide



The LEDs were arranged like so


_
I had to later remove the actual lens from the lenses attached on the colored lens (ie attached only the cylindrical black part) because otherwise everything below these LEDS would turn blue or red... _



Putting the LEDs together was quite straight forward.
Having borrowed the SENEYE par meter from my good friend @Jaap, it was about time for the critical readings... It was that same PAR meter that measured less than 40par at substrate with the T5 tubes.

Without the optics, readings were OK. Put some optics on and readings were way up high! So, I figured I would be hanging the LEDs high enough not to get in the way during maintenance, and then set the intensity to the desired level, to reach a reading of about 50par at substrate. 50par was a reading taken with the same apparatus on three very successful tanks.



Having confirmed that the new fixture will provide more than enough light than that needed, I was off at the acrylic shop. I got a 10mm acrylic, laser cut to 128 x 18 cm, with 30 x 25mm diameter holes laser drilled, for 60eur. Laser cut means that all edges were polished.

Couple of hours later, the fixture was hanging above the tank. At 100% intensity, hanging about 55cm from substrate (about 25cm from tank rim) I was getting > 100par at substrate! So, the intensity for all three channels was set to 50% to get the 50par reading.

*Controller*
The bundled controller allows to control up to 5 channels (ie 5 * 10 * 3w leds)
You can split the day into 5 sections, and then set the intensity for each channel during each section.
It also has a remote control (rf). Setup is also straight forward. Unfortunately you don't get the ramp up/ramp down to simulate dusk/dawn.

I have set the lights to run at 50% intensity 50par for 5 hours, with 1 hour in between running at 60% intensity (about 60par). Running the LEDs at about 50% will extend the life of the LEDs (I hope) and of course, LEDs run much cooler.

*Things to consider*
If you are using this seller and the supplied optics, make sure that you connect the LEDs (a led with another led) on the same spot as the LEDs are connected, on the star heat sink. This way, you will be able to attach the optics by clicking them in place. I did not do that, and had to file the black part of the optics then glue each lens in place.




*Total cost for this was about 250EUR*
135eur for LEDS, optics, drivers, controller
60eur for acrylic
20eur for aluminum
35eur for wiring, thermal paste, epoxy, wire rope, wire rope accessories

Thanks for reading!


----------



## Jaap (25 Apr 2016)

Wow! Bravo my friend! Only you... 

Sent from my SM-G900F using Tapatalk


----------



## Tim Harrison (25 Apr 2016)

Super smart...functional and something of a design statement.


----------



## Eduard18 (25 Apr 2016)

That looks top class! Great work ! The best looking DIY LED fixture !

Envoyé de mon SM-G935F en utilisant Tapatalk


----------



## Ryan Thang To (25 Apr 2016)

look awesome mate


----------



## Alex J (26 Apr 2016)

That looks very smart


----------



## Martin in Holland (26 Apr 2016)

I would buy one


----------



## Hamza (26 Apr 2016)

Nice build, I like the way acrylic is neatly concealing the wires, very aesthetically done.

Epoxy gluing the channels is a pretty neat idea . Is it the normal epoxy or epoxy heat sink comound?

There are a few doubts I have..
How are you running these LEDs parallel on constant current(CC) driver?

And the drivers are 38-42v each, right? So 10 LEDs on each driver gives you 3.8-4.2v of VF on each LED which seems to be on higher side. These Taiwanese LEDs maximum I have seen 3.6-3.8v, but usually they come in range of 3.0-3.6.

But in journals over the internet I have seen people maintain 3w LEDs at slightly lesser VF than what they are rated, that is around 3.0-3.3v which increases the efficiency and life of the chip. So, is this slightly higher VF causing any heat issues?(please keep us updated on this)

And I am surprised that you are driving the reds and blues on same line. The reds I purchased from various sources were rated at 2.0-2.8v, I ended up blowing a lot of reds and later read the spec sheet to find that they are rated at much lower VF. 

P.S. I was building a similar setup, but couldnt source any good CC drivers locally. I tried resistor with a SMPS power supply and it was producing pretty low light. So waiting for my CC drivers to be delivered.


----------



## Christos Ioannou (26 Apr 2016)

Hamza said:


> Epoxy gluing the channels is a pretty neat idea . Is it the normal epoxy or epoxy heat sink comound?


I used a normal epoxy labelled "liquid metal". I share the same concern as you, it would have been better if I used epoxy heat sink compound both for the sinks as well as to glue the leds in place,  instead of the messy thermal compound and epoxy. But, the led stars are in contact with all 4 u channels so I guess they pick up the heat efficiently. 



Hamza said:


> There are a few doubts I have..
> How are you running these LEDs parallel on constant current(CC) driver?
> 
> And the drivers are 38-42v each, right? So 10 LEDs on each driver gives you 3.8-4.2v of VF on each LED which seems to be on higher side. These Taiwanese LEDs maximum I have seen 3.6-3.8v, but usually they come in range of 3.0-3.6.
> ...


 too techy these questions for me but I will try to answer. 

There are 3 drivers,  each running 10 3w leds.  The drivers attach to a controller.  If you opt for say 60w bundle you get 2 drivers,  120w 4 drivers and so on.  Hence I concluded that the bundled drivers fit the bill and did not question this further. 

On "bench tests"  ie running leds to check for output/heat, I was running the leds @100% for 8 hours. Heat sinks got warm(not hot).  Now I am running the leds at 50% to get target output. I will try to get a temp reading tonight and let you know. 

Futher,  colored and white leds are all rated at 3w (unless I got it wrong). These are the bridgelux brand. No issues so far but definitely too soon to tell![/QUOTE]




Hamza said:


> P.S. I was building a similar setup, but couldnt source any good CC drivers locally. I tried resistor with a SMPS power supply and it was producing pretty low light. So waiting for my CC drivers to be delivered.


Good luck with this!  I am sure I would not be able to pull this one through if I had the same questions as you do.  I did approach this as if building LEGOs  and was naive enough not to question the bundled setup. Time is the ultimate test! 

Sorry if I could not better answer your questions,  thanks a lot for your interest in this build! 




Sent from my A0001 using Tapatalk


----------



## rebel (26 Apr 2016)

Best looking diy aquarium led I have seen! It's like the aesthetic of ADA with the power of radion! 

Durability will be the only question but being away from the water, it's got a good chance!

Manufacturers should take note!


----------



## Liana (26 Apr 2016)

Excellent craftsmanship!!!  WELL DONE!!!!!!!

I will be waiting for your next project.


----------



## Christos Ioannou (26 Apr 2016)

Hi @Hamza 

temp reading on heat sink,  where the led is attached with the heat compound,  is ~40'C, after 6hrs of operation. 

So it does run pretty cool I guess! 

question: running at 50% intensity means less power consumption?


----------



## rebel (27 Apr 2016)

Christos Ioannou said:


> Hi @Hamza
> 
> temp reading on heat sink,  where the led is attached with the heat compound,  is ~40'C, after 6hrs of operation.
> 
> ...


That's is a superb running temperature. Wonder how much it is at 100%.

If you are using PWM dimming (most likely are), then yes it would use about 50% less.


----------



## GreenNeedle (4 May 2016)

Looks superb.  Very nice job.


----------

