# DIY LED tank light



## illnastyimpreza (Jul 31, 2009)

I am looking to put together a LED light setup for my salt water fish tank.

I would like the light to be a mixture of 80% white LED, & 20% blue LED lights. would this be a good mix of color? The max total translucent area for the leds is 21'' x 3'', With another 3/4'' of covered material on the sides. So the LEDs would need to fit inside of a 21'' x 3.75'' area.

Do you guys have any good links to decent LED light strips that I could assemble to measure roughly that size?

I will also need a decent AC/DC power converter. It would preferably need to fit in the existing light hood of the tank... I've got prolly 3'' of hight off the top of the tank to work with. Any ideas on a decent power supply?

I am making the lights for both my 55 gallon freshwater tank, and my 20 gallon long salt tank.

any info would be awesome. Lemme know what you guys think !


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## brian102 (Aug 21, 2006)

no idea on the leds but for a power source a computer power supply may work good, only produces as much power as it needs, has 3.3,5 and 12 volts to work with to! i think that may be a good start? plus it would have a fan built in for cooling


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## guppyart (Jan 22, 2005)

LED lightstrips are now going to put out enough light for corals.
what guys are using for LEDs and reefing is CREE LEDs you can buy focusing lenses that will create a tighter beam and raise the intensity.
http://glassbox-design.com/2009/cree-xp-g/
http://www.reefcentral.com/forums/showthread.php?s=&postid=11488022
nanoreef.com forums have alot of hardcore LED knowledgeable people.


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## illnastyimpreza (Jul 31, 2009)

guppyart said:


> LED lightstrips are now going to put out enough light for corals.
> what guys are using for LEDs and reefing is CREE LEDs you can buy focusing lenses that will create a tighter beam and raise the intensity.
> http://glassbox-design.com/2009/cree-xp-g/
> http://www.reefcentral.com/forums/showthread.php?s=&postid=11488022
> nanoreef.com forums have alot of hardcore LED knowledgeable people.


those look interesting... but very expensive.

I am looking @ putting these guys lined up as close as I can get them. Whata u think ? http://cgi.ebay.com/2-x-Car-Bulbs-1...r_Truck_Parts_Accessories?hash=item4a9e264519


thanks for the links and info. I'm gonna surf around over there. I am really quite intreguied by the entire LED thing. There seems to be a HUGE markup on stupid simple LED lighting for Household use !


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## brian102 (Aug 21, 2006)

we sell those exact things at autozone , u can get red white and blue ones. they are really bright but idk if they are theright colors and stuff for corals, idk u coul dalways just try it!


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## Guest (Mar 3, 2010)

those things are REALLY small. u will need a whole load of them for a hood.


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## bmlbytes (Aug 1, 2009)

I got one of those Autozone lights in my car. They are bright enough for a dome light but I do not think they would be good for plants or corals. You may get decent lighting for physical viewing of the tank though. You will just need some sort of 12v power source, which is easily found. If you cant find one, go to Radio Shack and buy a 12v regulator and put it in-line with a power source that gives more than 12v (the packaging will explain the largest and lowest volts it will accept). If you put too many volts into it though, you may need a heatsink for the regulator.


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## Guest (Mar 3, 2010)

2 complicated. ask for a Step Down Converter. converts 110/220V to 12v.


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## TheOldSalt (Jan 28, 2005)

See?
I told you that the right kind of LED was going to be very pricey.

Osiris made an LED hood for his tank not to long ago. He can tell you how well it's been working and how much it cost and where to get parts and such. I'm sure he was able to build it for less than it would have cost to buy, even though he still spent a bundle.


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## bmlbytes (Aug 1, 2009)

Typically people use several 3 watt LEDs for their hoods. They require special lenses to get the correct spread of light to make it look even, and they also require heatsinks. The LEDs without the other things are expensive the way they are.

The Cree LEDs are the ones you want. The specific models are XP-G, XP-E, XR-E or the XR-C. These are the types of LEDs they use in super high powered flashlights.


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## illnastyimpreza (Jul 31, 2009)

bmlbytes said:


> I got one of those Autozone lights in my car. They are bright enough for a dome light but I do not think they would be good for plants or corals. You may get decent lighting for physical viewing of the tank though. You will just need some sort of 12v power source, which is easily found. If you cant find one, go to Radio Shack and buy a 12v regulator and put it in-line with a power source that gives more than 12v (the packaging will explain the largest and lowest volts it will accept). If you put too many volts into it though, you may need a heatsink for the regulator.


why would they not be good for corals??

I'm thinking I can fit at least 10 of them on each side of my 55 gallon tank. Thats GOTTA be enough light output...

Does anyone have any more info on exactly the right amount of Lumens, and color temp and whatnot that I would need for corals ?

whata u think of these ? http://www.oznium.com/led-piranha-bar


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## brian102 (Aug 21, 2006)

the last ones there, are not very close together


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## Mikaila31 (Nov 29, 2009)

illnastyimpreza said:


> why would they not be good for corals??
> 
> I'm thinking I can fit at least 10 of them on each side of my 55 gallon tank. Thats GOTTA be enough light output...
> 
> ...


LED's put out a lot of light, but not a lot as far as plants care. It can be done, but if you are talking live plants or corals then you need the expensive 3 watt LED's and lots, the little 3mm and 5mm LED's do not work. They will light your tank just fine, but will not provide the intensity needed for plants or corals, even very low light plants. 

When using LED's you still need about the same wattage as if you were using T5's. Its not really the wattage that is important, its gets really technical, but you need enough "plant friendly light". This is often measured as PAR or PUR. Just because there is light doesn't mean it is usable. Plants absorb blue, red, and a little yellow light. They reflect mostly green. You flood a plant with tons of green light it will still die, because it cannot utilize that light. White light is the combination of many different colors. When bulbs or LED's use a combination of colors they are called "full spectrum". Plants and corals need full spectrum light as they are dependent on a range of light. A T5, Cree, PC, ect will put out a spectrum that looks similar to this 

LED's at our current technology, can be full spectrum, but the ones you are looking at are not. Usually any good LED seller will tell you the wavelenght of the bulbs. Generally any 3mm and 5mm bulb is not they generally have one spike This is normally provided listed, like 625nm which would be a red LED. White LED's listed as white still have just a spike, here is a example. At the bottom of the page it shows the bulb peaks only at 450nm. When we first started trying to grow plants with LED's people did use the small ones, tons of them and they mixed colors. Usually white, red, and blue. Then came the CREE LED's I still don't fully get them, but they are full spectrum LED's and you can even pick kelvin ratings. And they are high powered.

Lumens are pointless, that corresponds exactly to how much light the human eye sees. We see mostly green, hence it is pointless to apply lumens to a plant that cannot use green light.


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## illnastyimpreza (Jul 31, 2009)

Mikaila31 said:


> LED's put out a lot of light, but not a lot as far as plants care. It can be done, but if you are talking live plants or corals then you need the expensive 3 watt LED's and lots, the little 3mm and 5mm LED's do not work. They will light your tank just fine, but will not provide the intensity needed for plants or corals, even very low light plants.
> 
> When using LED's you still need about the same wattage as if you were using T5's. Its not really the wattage that is important, its gets really technical, but you need enough "plant friendly light". This is often measured as PAR or PUR. Just because there is light doesn't mean it is usable. Plants absorb blue, red, and a little yellow light. They reflect mostly green. You flood a plant with tons of green light it will still die, because it cannot utilize that light. White light is the combination of many different colors. When bulbs or LED's use a combination of colors they are called "full spectrum". Plants and corals need full spectrum light as they are dependent on a range of light. A T5, Cree, PC, ect will put out a spectrum that looks similar to this
> 
> ...


wow that is some awesome info right there. Thank you for answering my question ! I really didn't understand why I couldn't just use TONS of regular LEDs....

do you think there are other full spectrum leds out there?... THose CREE's are expensive !


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## Mikaila31 (Nov 29, 2009)

They are still a decent price IMO. LED fixtures will be more expensive than a T5 fixture of similar wattage, you will not be able to avoid this. Even the DIY ones usually cost more. There are very few fixtures using the 3 watt high powered LEDs, that won't put you back a lot. The 3 watt LED's require drivers and other stuff. Here is a DIY thread, but you can find a couple online. I suggest you look for more and get an idea of what the most efficient way is to tackle the task. 

In the long run though a LED fixture should save you money. T5 and PC bulbs can be quite expensive. Most suggest replacing them every 8 months! I usually run mine over twice as long, before I replace them. Either way 3 of my 55 watt PC bulbs cost about $50. LED's should be good for an estimated 10 years and much longer if you slightly under drive them. You may have a few give out early, but the CREEs are usually good stuff. It is important to manage heat properly as these things get hot, and hot driver will need replacing sooner. 

I really have to say that LED's are a bad option on a 55gal, the 20 could be done for sure. LED's, even the 3 watt ones are not know for depths. IDK why this is really. You only see them used on small or shallow tanks. I have played with moonlights before and IMO they quickly loose their intensity over distance. I've yet to come across any PAR tests done on LED's though, but I'm sure they are out their. Its just not wise at this moment and time to do LED's on such a large and deep tank. IMO LED's will become much more mainstream in this hobby and hopefully cheaper down the road. Cuz I can't buy them anytime soon

You may want to look around and ask on forums where LED's are more common, but it is my understanding that CREEs are some of the best LED's for plants/reefs. I believe there are some other brands out there that are cheaper than the CREEs, they are still the 3 watt high powered LED's. But generally the cheaper ones have lower PAR values and such.


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## guppyart (Jan 22, 2005)

heh and to give you an idea when guys use 6ish cree LEDs for a 3g nano tank thats like 4"x4" you the 55g person are going to be looking at a small fortune to be able to get a decent light fixture for a 55g that will grow coral well.
honestly LEDs are currently to expensive to be used for mass lighting large tanks.
you would be better off buying a top quality T5HO light or going metal halide for anything that big.

LEDs do make an awsome alternative lighting source but its going to take a few years before designs are figured out, prices drop, etc


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## illnastyimpreza (Jul 31, 2009)

good stuff thanks guys. Currently my only Salt tank is my 20 gallon short long. Do you think It will work better due to being so short???

I read somewhere that regular "white" leds have blue in them as well.

Should I try using both white and blue Leds???


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## bmlbytes (Aug 1, 2009)

No, you will likely get 3 colors (white LEDs are LEDs that put out red, green and blue) out of those LEDs, which will not be enough to keep corals alive. 

Check out this part of Wikipedia. It will explain how the colors in LEDs work. The part on white LEDs is what you really need to understand. Also understand that the phosphor ones they talk about in the article are the expensive spectrum lighting ones. 
http://en.wikipedia.org/wiki/Light-emitting_diode#Colors_and_materials
It is hard to teach someone who doesn't know how LEDs work.


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