23 replies to this topic

[werdna]

Hey all

I wanted to see just how cheap I could make some LED lights.
So I bought $10 worth of ultra bright 6000mcd 40degree LEDs, made a simple unit and placed it on top of a tank.
Connected up to a $10 12v 1.5a power supply and let her rip!
The effect is really quite cool, I think. Quite similar to sunlight on the ocean floor.
Reason for this is because the light is so concentrated at the surface and my tank uses 2 sponge filters so there is heaps of movement at the surface.
Let me know what you all think.


And so you can see the full effect, I uploaded a video as well. (My shed isnt really that noisy, my camera really amplifies the sound)


Obviously to go brighter you just add another strip of lights.
I might try 3 strips next when I find the time.

I should be able to run between 4 and 6 tanks off the one power supply (depending on the number of strips), and draw no more that 18w.
The other great thing about them is that I can build them into a 25mm square channel, so if you have racks like I do, they take up hardly any space and can be mounted onto the stand above.

Cheers

Andrew

[lawdog]

Too cool Andrew,
but where did you grab the LED's from and got a shot of the mounting frame.

Cheers.

[werdna]

The mounting frame is a plank of wood with some holes drilled in it at the moment.
I am about to get a length of ali to make a purdy frame!

The leds I got off one of my suppliers over east.
They are your standard 5mm led, volt range between 2.9 and 3.5.

I am running them on 3.3v atm. In my experience they can be really picky about voltage so I didnt want to run them on the max 3.5v.
I also used a switchmode style power supply instead of transformer based, mainly cos it is cheaper.

[mark]

that looks so cool it would look great on my reef tank at night good job

[werdna]

I can get the LEDs in blue as well. Probably would look good at night. Might try that next!
I can now get 12000 lumen ones too, but they cost a little more.
They would mean the whole light could be done for around $50 using 3 rows and would draw around 3.5w.
I'm ordering some more soon...

[Den]

Fantastic Andrew, thanks for sharing, Im using skylights in my fishroom but the tanks could use some extra lighting. I was put off lighting because of the power consumption, I knew that LEDs were efficient but had no idea they were that efficient. I now think LEDs will be the way forward for me too.

Cheers
Den

[werdna]

Cheers Den.
I'll let you know when I have finished my frame and you can check it out if you want.
They draw so little power that they stay lit for a second when you unplug the power supply while the caps discharge. And being switch mode the caps aren't that high a value either.
When I was working out the consumption at first I thought I had stuffed up the maths. It seemed too low. I had to plug in my multimeter to confirm it. But the unit now draws 90mA, so at 12v is 1.08w.

The light now is using 12 leds, but even if I triple the amount it will still draw a tenth of a fluro and last longer. And be cheaper than buying a fluro light in the first place.

[Den]

Seems the LED can beat metal halide in every aspect, found this interesting article.

http://www.aquarists...ight-of-choice/

[Neakit]

they don't beat them in every aspect, mh are cheaper to setup and aren't sensitive to power fluctuations. They can have more light output if the correct ones are chosen, and they have issues with spotlighting.

[werdna]

Power fluctuations are quite easy to fix.
If you are running a 12v setup you simply use a 13.8v power supply and run it thru a 12v regulator first. A high value cap before the regulator can also help for power drop outs.
It will increase setup cost by around $2.

If you are running a higher voltage you can use a zener diode in a crowbar circuit to burn excess voltage thru a resistor.

But Perth power is pretty good, we dont really suffer from power fluctuations, it isnt like power in a car, and LEDs are no more sensitive than components in monitors, tvs etc.

Next time I place an order over east I am going to order 100 x 10000 lumen white and 25 x 3000 lumen blue ones and I'll do some experimenting.
However I dont have marine or plants, so the idea wasnt for growth, it was cheap efficient lighting.

One thing I am wondering about. I have never kept coral, so dont understand the whole light part properly. But doesnt coral just need a colour with a high kelvin rating, bringing it close to the blue end of the light spectrum due to water removing the red in light?
If so, couldnt a coral light be made simply by changing the number of, or brightness, of blue leds?
For example, if I made a strip up consisting of 1 blue for every 2 white leds, I would assume that would bring me close to around 10000-12000 kelvin colour temp, and if I made up a simple dimmer circuit for the blues you could reduce the colour temp if you wanted.
I could also have the blues on a separate circuit to simulate a moon light.
It just seems to me that for around the $100 mark you could build a LED light unit for a 4ft coral tank that would be just as bright as metal halide, the right colour temp, runs cool, draws less than 15 w, no maintenance, the list goes on.
It would need to sit around 300mm above the tank, but doesnt a mh need to anyway for heat dissipation?

I could be wrong, but would be willing to offer a test unit to someone willing to give it a go once I pull my finger out and give it a go...

[Skuts]

Out of interest did you mean lumen or mcd (mili candela) because they are 2 different types of measurement

I recently did a led light using water proof led strips they work awesome and consume next to no power

If your interested I used some math to work out how much light I needed. 6000 lumens per square meter of tank shinning through 750 mm of water which worked well since my tank is 4x2x18 I needed around 2590 lumens

In regards to led for coral I believe red and blue works a treat if you wanted to you could independently dim each colour to control the colour temp

Good luck with it all

[Neakit]

no with coral its not necessarily the colour. What your after is Par or photosynthetically available radiation. The blue is only for your viewing pleasure. If you break down the spectrum of a 5k light you will find that it still will provide the same amount of light needed as a 10k one does. all that the 10k one does is limit the spectrum that are considered unnecessary (focusing in the blue more). With leds people are using royal blue leds and cool white ones(5k). Also with coral depending on what you keep depends on the intensity of light you require. There are people who are using leds above their tanks and are having great results, But their power draw is in the same vicinity of Mh, they just don't have as much heat. (high powered leds produce alot of heat) I have looked into this area myself but the issue i have had is that the technology is changing so fast that any fitting bought is superseded with in 3 months, and that the cost of a Australian appliance approved one cost a fortune and aren't that flash.

[werdna]

Oops, Yep its mcd. The book says it is luminence. I assumed luminence is measured in lumens, turns out its not
How obvious!

Fair enough with the coral... I think I have decided... stuff it, I'll stick to fresh water and fish

[werdna]

Decided to try every led I had, in total 32, on one 4ft.
I have 2 evenly spaced centre supports on my tank rack, so figured one group in each.
I figured the best number would be 12 per group, but was 4 short, so ended up with 12 on each side and 8 in the middle.
Turns out I was right, it needs 12 per 1/3rd, you can see the middle is not as bright. Its amazing the diference 4 leds make!
But I am happy with the result.
The sides are definately bright enough.


Total cost for the setup if I used all 36 leds including resistors and the ali frame I am making is going to be around $60.
Total current draw now is a little under 200mA, so I would say with all 36 leds it would be 215mA which works out to a massive 2.6w.
My plug pack is rated at 1.5amp, which means it could easily run 6 tanks.\

The other major advantage is there will be 6 less 240v appliances around my tanks. Power cords behind racks tend to look pretty scary!

I might order in a 13.8v 1.5a plug pack with my led order though, as that would run a string of 4 leds, instead of the 3 I am running now.
Just makes wiring it up easier, seen as I want 3 rows of 4 leds.

Opinions?

Andrew

[Skuts]

Looks great mate

Try looking on eBay at the superbright store they have some good really bright led for cheap I was going to go that way originally but went a slightly different route

[werdna]

I looked on ebay, and they are cheaper, but I know I can get warranty and data sheets from my supplier.
And I know that when they say it is 6000mcd, it really is 6000 mcd...

[jslayz]

Good one and kudos to you!!!

With my LEDS to light my 1400L tank I only draw about 25W.
To light it to crazy brightness at maximum (which is too much) it runs only 100w.

At my LFS I was recommended to grab 4 T5's to light this tank and each one was 48W and could not be dimmed but you could switch off run 1 of the 2 bulbs in each unit.
As mine has been running for a year now and I have not had to replace any bulbs I've saved (8 x 24W T5HO tubes at $33 each) $264 in bulb replacements already.

Perhaps you might like to add a dimmer, I found it really nice to be able to vary the intensity.
As you seem to know what you are doing, you may be able to add a timed multi level dimmer?

Great to see more people having a crack at leds and everyone trying a different avenue, very cool.

Keen to see where you go next.

J

[werdna]

Cheers J!

A dimmer is simple.
I have thought of different circuits, and they are all fairly easy to make.
One was a resistor capacitor network to make a soft start circuit, so when the lights are on a timer, instead of coming on full brightness straight away, they gradually come on over around 20 mins, might be a bit nicer for the fishies.

A few years ago I designed a 24 hour lighting schedule, with 4 separate circuits, so I could have a small light on one side come one for 1 hour in the morning, then switch to the main light for 10 hours, switch to a small light on the other side for 1 hour, then 12 hour moon light.
Then my tanks got moved to the shed instead!
Having no tanks in the house means I dont really have to worry about different circuits.

When calculating your savings, dont forget to include power saved.
You are saving 167w per hour, on a 12 hour a day circuit over 1 year that is $160 per year, thats $424 per year with tubes. You will pay off your circuit in 3 years, and that doesnt include what the fluro setup would have cost to start with.

Once I finish this semester at uni I'll be building the setup into the racks, and because I can build it into 20/25mm ali tube it will sit flush with the steel frame. You wont be able to see where the light is coming from. What more can you ask for?!

[jslayz]

Hot damn!
Pictures when it's installed pleeease.

[werdna]

Ordered in some sealed waterproof LED light strips from China.
6 Strips cost me around $36 delivered.
I havent made up a proper mount for them yet, however I have connected them for a looksy.

Lights, they are surface mount LEDs with 3M tape on the back for mounting, easy!


Close up


Comparing 3ft fluro (top tank) to 2 strips connected in parallel (bottom tank)


Tank with LED, I left the shutter open for 1/2 a sec so you can see how the lights really look, means the fish are blurry tho


Same tank with 3 strips instead of 2, the difference is pretty noticeable, I would say 2 strips are ok for a shed, but 3 stips for a display tank.


Each strip draws around 300ma, so 3.6w per strip.
A little more than I was expecting, but still much better than a fluro.
I'll post pics of the whole unit when I get round to making up the mounting frame.

Cheers

Andrew

Edit: spelling...

Edited by werdna, 04 February 2011 - 10:40 AM.