Questions for DIY LED Light Fixture

Reefing Newbie · 12/28/2011, 08:09 PM

I have decided to build myself a LED light fixture to replace my VHO lighting fo rmy 125 gallon tank(72"x18"x24"). The VHOs really don't give me the shimmer or penetration I will need to grow SPS and LPS colonies, a Maxima Clam, or a LTA. Plus the bulbs need replacing every 8-12 months, not sure though

.

Any ways as for my design I was planning on spreading the LEDs out over three heatsinks. Each would probably be 8.460"x18". Let me know if I can go smaller or if I need to go bigger. My goal would be to get as much of the spectrum of lighting as I can meaning using some of various colors, but mostly royal blue and all the whites to get the spectrum. To start how many LEDs would you recommend I use to grow the corals and inverts I listed above? 72 LEDs with 24 per heatsink, or 96 LEDs with 32 per heatsink, or somewhere in the middle? Would using red and green LEDs be benificial or harmful to the tank as far as algae growth is concerned? I would like to use 8 violets, 3-6 reds, and 3-6 greens but I am not sure quite yet. The reds(if used) would be the first to come on with the greens and purples as well as the last to go off to simulate sunset. Maybe some whites at the same time as well. Then blues would slowly come on, then whites to everything getting to the power I have set(pending on if I am acclimating corals). Give me your suggestions please as well as tips and advice on how to get a good set up. Looking to get my color temp to be between 15 and 20K, so white and blue recommendations welcome!

James77 · 12/28/2011, 08:25 PM

96 is up there in number. I had 78 on my 120g and if I were to build it again I would most likely do 50-60. I would consider maybe 70-80 on your setup.

Just another option to heatsink, you may have more luck spreading them out is you use channel aluminum instead. Just as effective as a typical heatsink, they are cheaper and allow full runs along the length of the tank. I had used the 1/8" thick, 1 inch wide with a "fin" height of 1/2".

http://www.speedymetals.com/c-8348-6063.aspx

Reefing Newbie · 12/28/2011, 08:39 PM

With my tank's top rim having 2 bars running front to back I think they would block the light from part of the full run. I am not sure though, so your idea is defiantly an option. Thanks for that idea. As far as number I will go 75 or 78 LEDs.

In my first post I forgot to mention that I plan on keeping them 6-8" above the water. What degree optics would you recommend? I was told 80 degree optics by Reef LED Lights.

reefereef · 12/28/2011, 08:46 PM

Get a mix of optics, i run 80,60,40 degree over my tank, this way i can get less intense light where the rock work is higher. I run 120 LEDS over my 8'x2' tank and use aluminum channel that is 7' long and run 5 of them spaced about 3" apart or so. Works really well too. I would think that 3 rows of 20 leds would work for ya, or if you want to run 78 like you said then maybe run a extra row in the front and back and spread out the other 18 leds there with 80* optics. I have my lights about 7" above the water.

Reefing Newbie · 12/28/2011, 09:46 PM

Could I get pictures of your fixture reeferreef? The ones in back will probably be cut shorter so I don't place any lights above the overflow boxes either.

reefereef · 12/28/2011, 10:28 PM

here's one trying to show the rows in the hood

and here's one showing the width of the leds strips

Reefing Newbie · 12/28/2011, 10:42 PM

You may have me sold on the channel aluminum. I don't know though, definantly something that I have to think about further. How do you cool them? I know that with a heatsink you can simply put something like a computer fan on top to cool them off. Which I may go with 1 long heat sink, but I like to looks of what I pictured the three 18" heatsinks looking like connected with aluminum L brackets(the longer ones) where I could simply attatch to the inside of the canopy I will be building for my tank.

BTW, very nice tank you have!

reefereef · 12/28/2011, 11:24 PM

I use two 120mm 12vdc fans, one on each end of the hood, if you look at the right side of the pic, second pic, you can see the bottom part of the ducting that i built for the fans. Due to space constraints i had to mount the fans at an angle to the rows of leds, i then cut and bent some aluminum to make the ducting. the intake for the fans in the top of the hood, also has ducting from the fans to the intake slots. My tank is about 90% sealed off from the room so no humidity or smells makes it to the family room.

With my two fans i have never seen more than 95ºF with my thermometer probe on the backside of the aluminum channel centered over the led.

The channel i am using is old aluminum window frame material from my local scrap yard, is like 1.25" and .5" tall and has either 3 or 5 fins. i have two different styles and noticed zero difference in cooling between the two.

I enjoy helping people not buy expensive heatsinks because they are not needed with proper airflow. it doesnt take much material to cool these LEDS and a little fan and the proper airflow goes a long ways.

biecacka · 12/28/2011, 11:34 PM

you could search in the DIY forum as there a ton of threads about it
corey

Reefing Newbie · 12/28/2011, 11:48 PM

I haven't seen any with the take I am thinking of. For me it is looking into the actual pieces as opposed to how to put it together. The ideas of the aluminum channels is great and I will actually be getting those for my tank. Now that I have mounting pretty much out of the way I would like input on the LED color. Would my plan work with 78 LEDs while adding red, violet, and green?

reefereef · 12/29/2011, 12:29 AM

cant help you with the other colors. i run whites and royal blues. i have read that red leds promote algae growth. if you think about it, really think about it, how can you even distribute reds greens, and violets into the lighting scheme. it would have to be a 1:1:1:1 ratio in order for the other color leds to have even spread, and what would you be gaining. I read an interesting article on how i guy took different leds, flashlight style and the effects were not what he thought i would be, point being, mix natural whites, cool whites, royal blues,and blue blues, and call it a build. or just mize the two whites and royal blues and enjoy it. dont over-complicate things. i use natural white and royal blues and like all the colors i get.

Reefing Newbie · 12/29/2011, 11:53 AM

I see. Thanks for pointing that out. I do want the violets because someone in my reef club has some violets mixed in on his and I think it makes the red corals pop. So my mix will be cool white, natural white(is this like daylight at 6500K?), blue, royal blue, and violets.

12/28/2011, 08:09 PM	#1
Reefing Newbie Registered Member. Join Date: Jul 2011 Location: Minnesota Posts: 2,435	Questions for DIY LED Light Fixture I have decided to build myself a LED light fixture to replace my VHO lighting fo rmy 125 gallon tank(72"x18"x24"). The VHOs really don't give me the shimmer or penetration I will need to grow SPS and LPS colonies, a Maxima Clam, or a LTA. Plus the bulbs need replacing every 8-12 months, not sure though . Any ways as for my design I was planning on spreading the LEDs out over three heatsinks. Each would probably be 8.460"x18". Let me know if I can go smaller or if I need to go bigger. My goal would be to get as much of the spectrum of lighting as I can meaning using some of various colors, but mostly royal blue and all the whites to get the spectrum. To start how many LEDs would you recommend I use to grow the corals and inverts I listed above? 72 LEDs with 24 per heatsink, or 96 LEDs with 32 per heatsink, or somewhere in the middle? Would using red and green LEDs be benificial or harmful to the tank as far as algae growth is concerned? I would like to use 8 violets, 3-6 reds, and 3-6 greens but I am not sure quite yet. The reds(if used) would be the first to come on with the greens and purples as well as the last to go off to simulate sunset. Maybe some whites at the same time as well. Then blues would slowly come on, then whites to everything getting to the power I have set(pending on if I am acclimating corals). Give me your suggestions please as well as tips and advice on how to get a good set up. Looking to get my color temp to be between 15 and 20K, so white and blue recommendations welcome!

12/28/2011, 08:25 PM	#2
James77 Registered Member Join Date: Aug 2005 Location: Rhode Island Posts: 8,158	96 is up there in number. I had 78 on my 120g and if I were to build it again I would most likely do 50-60. I would consider maybe 70-80 on your setup. Just another option to heatsink, you may have more luck spreading them out is you use channel aluminum instead. Just as effective as a typical heatsink, they are cheaper and allow full runs along the length of the tank. I had used the 1/8" thick, 1 inch wide with a "fin" height of 1/2". http://www.speedymetals.com/c-8348-6063.aspx __________________ Jim Current Tank Info: 120g Mixed Reef and 75g Freshwater

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12/28/2011, 08:39 PM	#3
Reefing Newbie Registered Member. Join Date: Jul 2011 Location: Minnesota Posts: 2,435	With my tank's top rim having 2 bars running front to back I think they would block the light from part of the full run. I am not sure though, so your idea is defiantly an option. Thanks for that idea. As far as number I will go 75 or 78 LEDs. In my first post I forgot to mention that I plan on keeping them 6-8" above the water. What degree optics would you recommend? I was told 80 degree optics by Reef LED Lights.

12/28/2011, 08:46 PM	#4
reefereef Registered Member Join Date: Jul 2011 Posts: 325	Get a mix of optics, i run 80,60,40 degree over my tank, this way i can get less intense light where the rock work is higher. I run 120 LEDS over my 8'x2' tank and use aluminum channel that is 7' long and run 5 of them spaced about 3" apart or so. Works really well too. I would think that 3 rows of 20 leds would work for ya, or if you want to run 78 like you said then maybe run a extra row in the front and back and spread out the other 18 leds there with 80* optics. I have my lights about 7" above the water.

12/28/2011, 09:46 PM	#5
Reefing Newbie Registered Member. Join Date: Jul 2011 Location: Minnesota Posts: 2,435	Could I get pictures of your fixture reeferreef? The ones in back will probably be cut shorter so I don't place any lights above the overflow boxes either.

12/28/2011, 10:28 PM	#6
reefereef Registered Member Join Date: Jul 2011 Posts: 325	here's one trying to show the rows in the hood and here's one showing the width of the leds strips

12/28/2011, 10:42 PM	#7
Reefing Newbie Registered Member. Join Date: Jul 2011 Location: Minnesota Posts: 2,435	You may have me sold on the channel aluminum. I don't know though, definantly something that I have to think about further. How do you cool them? I know that with a heatsink you can simply put something like a computer fan on top to cool them off. Which I may go with 1 long heat sink, but I like to looks of what I pictured the three 18" heatsinks looking like connected with aluminum L brackets(the longer ones) where I could simply attatch to the inside of the canopy I will be building for my tank. BTW, very nice tank you have!

12/28/2011, 11:24 PM	#8
reefereef Registered Member Join Date: Jul 2011 Posts: 325	I use two 120mm 12vdc fans, one on each end of the hood, if you look at the right side of the pic, second pic, you can see the bottom part of the ducting that i built for the fans. Due to space constraints i had to mount the fans at an angle to the rows of leds, i then cut and bent some aluminum to make the ducting. the intake for the fans in the top of the hood, also has ducting from the fans to the intake slots. My tank is about 90% sealed off from the room so no humidity or smells makes it to the family room. With my two fans i have never seen more than 95ºF with my thermometer probe on the backside of the aluminum channel centered over the led. The channel i am using is old aluminum window frame material from my local scrap yard, is like 1.25" and .5" tall and has either 3 or 5 fins. i have two different styles and noticed zero difference in cooling between the two. I enjoy helping people not buy expensive heatsinks because they are not needed with proper airflow. it doesnt take much material to cool these LEDS and a little fan and the proper airflow goes a long ways.

12/28/2011, 11:34 PM	#9
biecacka Registered Member Join Date: May 2008 Location: Columbus Ohio Posts: 6,361	you could search in the DIY forum as there a ton of threads about it corey

12/28/2011, 11:48 PM	#10
Reefing Newbie Registered Member. Join Date: Jul 2011 Location: Minnesota Posts: 2,435	I haven't seen any with the take I am thinking of. For me it is looking into the actual pieces as opposed to how to put it together. The ideas of the aluminum channels is great and I will actually be getting those for my tank. Now that I have mounting pretty much out of the way I would like input on the LED color. Would my plan work with 78 LEDs while adding red, violet, and green?

12/29/2011, 12:29 AM	#11
reefereef Registered Member Join Date: Jul 2011 Posts: 325	cant help you with the other colors. i run whites and royal blues. i have read that red leds promote algae growth. if you think about it, really think about it, how can you even distribute reds greens, and violets into the lighting scheme. it would have to be a 1:1:1:1 ratio in order for the other color leds to have even spread, and what would you be gaining. I read an interesting article on how i guy took different leds, flashlight style and the effects were not what he thought i would be, point being, mix natural whites, cool whites, royal blues,and blue blues, and call it a build. or just mize the two whites and royal blues and enjoy it. dont over-complicate things. i use natural white and royal blues and like all the colors i get.

12/29/2011, 11:53 AM	#12
Reefing Newbie Registered Member. Join Date: Jul 2011 Location: Minnesota Posts: 2,435	I see. Thanks for pointing that out. I do want the violets because someone in my reef club has some violets mixed in on his and I think it makes the red corals pop. So my mix will be cool white, natural white(is this like daylight at 6500K?), blue, royal blue, and violets.