LED Optics Selection?

reeferdale · 12/20/2011, 10:30 AM

Hi all,

I need to order optics for my LED rig and I could use some advice/input from the LED experts. Here is what I have:

Tank: 72" L x 36" W x 24" H
I am using six 18" x 10" heatsinks. Each sink has 42 LEDs spread evenly. I have 132 CW and 120 RB (Cree XP LEDs)
I will have 4.5" of space between the sinks from side to side and 5.25 of space between the sinks from front to back.
With this in mind, I am debating between 40, 55 or 80 degree optics. I can hang the fixture anywhere from 6" to 18" over the tank.
This is a mixed reef, heavy on SPS (acro, monti) many chalices, and assorted zoas, shrooms, plates, brains and frogspwan coral.

I was originally leaning towards using 65 degree for the whites and 55 for the blues.
My main concern is I don't want to spill a lot of light out of the tank, and I would like to be able to have really high PAR. I am afraid of spotlighting if I use all 40 degree optics. Since these are dimmable, I can control the white and blues to dial back the intensity. Initially the blues will be run around 800 mA and the whites around 650 - 700 mA

I would like to use all the same degree optics, but I can mix them up if it would be beneficial. Anyone that has experimented with optics that could lend some advice or an opinion I would appreciate their input.

Thanks
Dale

reefereef · 12/21/2011, 10:57 AM

Run 40* on the perimeter and. Where the rock is low, run the 55* most everywhere else and 80* over places where the rock is tall and places where you don't want to blast corals.

This is how mine are setup and I get very very little light spilling onto the tank walls, the light starts hitting the tank right where the bottom glass hits the side.

grinder4400 · 12/21/2011, 01:50 PM

Does your tank have euro braces? Ive never built one of these;however, I'm in the process of making one...thought it interesting how many LEDs your build has. Thats alot of LEDs. A meanwell 48d/p drives 14 3w xp-g's ...thats at least 10 drivers for just the cool whites.
I plan to build a test light to see how much is needed and try different lenses. Very interesting to see reefereef's post on combinations of lenses used.Please let us know which way you go. Here is a pic on my rough design. not to scale. withe w-rb ratio should be around 8-12k. here are thee different thoughts..

I only have 8 feet of heat sink. each piece is 16"x4.75 Fins are nice though. I understand cree recommends 2" inch's of surface per watt for heat precipitation.

reefereef · 12/21/2011, 07:20 PM

dont get super wrapped up in the heatsinks, i used some aluminum window frame that i found at the scrap yard, it is about 1 1/4" wide and has 5 fins on the back side. Works like a charm and only ran me 10$ for 35' worth.

Northside Reef · 12/21/2011, 09:45 PM

Hi Dale, I am very very new at this myself and have been wrestling with a similar problem.

I think I just over complicated the question and only when I sat down and thought about it did it make any sense to me. For my issue it was can I run a single track down the center of the tank and light the entire tank top to bottom. But the formula is the same for both of us.

Here is the layout I used for 55 degree lenses.

A single 55 degree lens.

two lenses 8.5" apart:

Of course I spill a ton of light out of the tank but the light is less intense the further it gets outside the center of the cone so I am not sure if it matters.

Jonboymd · 12/21/2011, 10:32 PM

And I told my geometry teacher that I would never use it in the real world......

reeferdale · 12/22/2011, 08:33 AM

Quote:

Originally Posted by grinder4400

Does your tank have euro braces? Ive never built one of these;however, I'm in the process of making one...thought it interesting how many LEDs your build has. Thats alot of LEDs. A meanwell 48d/p drives 14 3w xp-g's ...thats at least 10 drivers for just the cool whites.
I plan to build a test light to see how much is needed and try different lenses. Very interesting to see reefereef's post on combinations of lenses used.Please let us know which way you go. Here is a pic on my rough design. not to scale. withe w-rb ratio should be around 8-12k. here are thee different thoughts..

Yes I have very wide euro bracing on top - I am hanging the LEDS right across the bracing. Others have done this and reported no issues. Keep the top clean of salt and they will penetrate the acrylic. My drivers are dimmable so I can adjust the light intensity, start low and raise it to where everythign is happy. If I can run these at 400 - 600 mA and accomplish that then that would be fine. One of the reasons I have so many LEDs is because the tank is 36" wide, many of the (180 gal) 72x24 builds I have seen are using 120 - 180 LEDs, since I have an extra 12" x 72" width to cover, that is why I have the extra LEDs. You are showing 72 LEDs for a 72x18 tank, if you double the size to 72x36 it you would need 144, and bump it up for a ton of high PAR for SPS I think you would be into the 200+ range. I think a lot has to do with what corals you plan to keep as much as the area you need to cover

for others, I would be careful about running 10 - 20 of the 48-60 meanwells. I have heard 6 - 7 is probably the max. There are articles here and online about harmonic distortion and heat build up. If you are running that many LEDs I would look at series/parallel wiring. I am running 4 meanwell HLG-240-48B drivers. They are 48Watt 5 mA drivers. I can run 132 whites from drivers 1 & 2 (66 each) at up to 800 mA and 120+ blues off the other two drivers (60 each) at over 800 mA. These have PFC (power factor correction) built in, the smaller meanwells do not.

reeferdale · 12/22/2011, 08:41 AM

Quote:

Originally Posted by Northside Reef

Hi Dale, I am very very new at this myself and have been wrestling with a similar problem.

I think I just over complicated the question and only when I sat down and thought about it did it make any sense to me. For my issue it was can I run a single track down the center of the tank and light the entire tank top to bottom. But the formula is the same for both of us.
Here is the layout I used for 55 degree lenses.

wow, thanks Northside! awesome rendering.
Since I have about 5" - 6" around the tank, the 55* looks like it would be OK for the edges. Again a lot of this depends on how high I hang the fixture.

I think I am going with no optics to start, I will take others advice and once I get all my livstock setup, I will add specific optics where/as I need them. Thanks for the geometry, I have one obtuse question, what specifically do the numbers represent, is this the depth and width of the spread in inches? seems unbelievable these spread 4'

thanks again

Northside Reef · 12/22/2011, 09:44 AM

Yes, all of the numbers are in inches. They do spread that much but of course the further away the less intense the light will be. Also the further from the center of the cone the more light is lost. So you would need to add a lot of LEDs in my situation to compensate for that.

SC Reefaholic · 12/22/2011, 12:30 PM

dale, that is a lot of LEDs. It was my understanding that 1 per 12 square inches of surface could grow anything and for LPS and softies it was more like 1 per 15 to 20 square inches. You are at 1 per 10 with that setup. I would be careful with the optics in the beginning. You are likely to melt any softies and possibly LPS if you go full bore. I would try no optics to start and then add according to need. Again, its my understanding that you want to be able to drive the LEDs at a decent clip to keep the temps in normal operating range whatever that is. If you use optics too strong you wont be able to turn them up. Just a thought form a fellow DIY'r.

I went with the HLG 100 & 120 on my build with 4 strings on the blue driver and 2 strings on the white driver. No optics and the LEDs at 12 inches off the tank. Love them!

reeferdale · 12/22/2011, 04:20 PM

QUOTE=SC Reefaholic;19657124]dale, that is a lot of LEDs. It was my understanding that 1 per 12 square inches of surface could grow anything and for LPS and softies it was more like 1 per 15 to 20 square inches. You are at 1 per 10 with that setup. I would be careful with the optics in the beginning. You are likely to melt any softies and possibly LPS if you go full bore. I would try no optics to start and then add according to need. Again, its my understanding that you want to be able to drive the LEDs at a decent clip to keep the temps in normal operating range whatever that is. If you use optics too strong you wont be able to turn them up. Just a thought form a fellow DIY'r.

I went with the HLG 100 & 120 on my build with 4 strings on the blue driver and 2 strings on the white driver. No optics and the LEDs at 12 inches off the tank. Love them![/QUOTE]

I hear you. I posted above - I think I am going with no optics to start, I will take others advice and once I get all my livstock setup, I will add specific optics where/as I need them. I know it seems like a lot of LEDs but being that the tank is 36" wide, I had to add at least 1 additional rows of LEDs to my design (32 LEDs) to be sure I could get front to back coverage, I added 2 rows (64 LEDs) to be safe. Also, I can hang this as high as 2 feet with no problems. So for a standard 180 tank (72x24) most people are in the 140 to 180 LED range, if you add in the adddtional 64 I would be at 208 to 248. So yah, maybe I have some extra LEDs! As my wife always says, bigger is better

I will just ramp them up to where they need to be and then setup the apex and let em grow. I figure I if I only run them at 400 - 600 mA then that is less stress on the LED and the drivers will not be close to maxing out either.
I would rather dial them down than have to re-do the thing and add more LEDs later.

12/20/2011, 10:30 AM	#1
reeferdale Registered Member Join Date: Feb 2009 Location: Southeast Michigan Posts: 165	LED Optics Selection? Hi all, I need to order optics for my LED rig and I could use some advice/input from the LED experts. Here is what I have: Tank: 72" L x 36" W x 24" H I am using six 18" x 10" heatsinks. Each sink has 42 LEDs spread evenly. I have 132 CW and 120 RB (Cree XP LEDs) I will have 4.5" of space between the sinks from side to side and 5.25 of space between the sinks from front to back. With this in mind, I am debating between 40, 55 or 80 degree optics. I can hang the fixture anywhere from 6" to 18" over the tank. This is a mixed reef, heavy on SPS (acro, monti) many chalices, and assorted zoas, shrooms, plates, brains and frogspwan coral. I was originally leaning towards using 65 degree for the whites and 55 for the blues. My main concern is I don't want to spill a lot of light out of the tank, and I would like to be able to have really high PAR. I am afraid of spotlighting if I use all 40 degree optics. Since these are dimmable, I can control the white and blues to dial back the intensity. Initially the blues will be run around 800 mA and the whites around 650 - 700 mA I would like to use all the same degree optics, but I can mix them up if it would be beneficial. Anyone that has experimented with optics that could lend some advice or an opinion I would appreciate their input. Thanks Dale Last edited by reeferdale; 12/20/2011 at 11:11 AM.

12/21/2011, 09:45 PM	#5
Northside Reef Premium Member Join Date: Mar 2004 Location: Chanhassen, MN Posts: 1,294	Hi Dale, I am very very new at this myself and have been wrestling with a similar problem. I think I just over complicated the question and only when I sat down and thought about it did it make any sense to me. For my issue it was can I run a single track down the center of the tank and light the entire tank top to bottom. But the formula is the same for both of us. Here is the layout I used for 55 degree lenses. A single 55 degree lens. two lenses 8.5" apart: Of course I spill a ton of light out of the tank but the light is less intense the further it gets outside the center of the cone so I am not sure if it matters. __________________ Back again for more fun! See how much fun by checking out my home page. Current Tank Info: 280 Gallon Display, 92 gallon Cube Clown and anemone tank. 700 gallon filter shed that ties it all together.

12/22/2011, 09:44 AM	#9
Northside Reef Premium Member Join Date: Mar 2004 Location: Chanhassen, MN Posts: 1,294	Yes, all of the numbers are in inches. They do spread that much but of course the further away the less intense the light will be. Also the further from the center of the cone the more light is lost. So you would need to add a lot of LEDs in my situation to compensate for that. __________________ Back again for more fun! See how much fun by checking out my home page. Current Tank Info: 280 Gallon Display, 92 gallon Cube Clown and anemone tank. 700 gallon filter shed that ties it all together.

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12/21/2011, 10:57 AM	#2
reefereef Registered Member Join Date: Jul 2011 Posts: 325	Run 40* on the perimeter and. Where the rock is low, run the 55* most everywhere else and 80* over places where the rock is tall and places where you don't want to blast corals. This is how mine are setup and I get very very little light spilling onto the tank walls, the light starts hitting the tank right where the bottom glass hits the side.

12/21/2011, 07:20 PM	#4
reefereef Registered Member Join Date: Jul 2011 Posts: 325	dont get super wrapped up in the heatsinks, i used some aluminum window frame that i found at the scrap yard, it is about 1 1/4" wide and has 5 fins on the back side. Works like a charm and only ran me 10$ for 35' worth.

12/21/2011, 10:32 PM	#6
Jonboymd Registered Member Join Date: Dec 2011 Location: Plainview, TX Posts: 10	And I told my geometry teacher that I would never use it in the real world......

12/22/2011, 12:30 PM	#10
SC Reefaholic Registered Member Join Date: Apr 2011 Location: Chapin, SC Posts: 410	dale, that is a lot of LEDs. It was my understanding that 1 per 12 square inches of surface could grow anything and for LPS and softies it was more like 1 per 15 to 20 square inches. You are at 1 per 10 with that setup. I would be careful with the optics in the beginning. You are likely to melt any softies and possibly LPS if you go full bore. I would try no optics to start and then add according to need. Again, its my understanding that you want to be able to drive the LEDs at a decent clip to keep the temps in normal operating range whatever that is. If you use optics too strong you wont be able to turn them up. Just a thought form a fellow DIY'r. I went with the HLG 100 & 120 on my build with 4 strings on the blue driver and 2 strings on the white driver. No optics and the LEDs at 12 inches off the tank. Love them!

12/22/2011, 04:20 PM	#11
reeferdale Registered Member Join Date: Feb 2009 Location: Southeast Michigan Posts: 165	QUOTE=SC Reefaholic;19657124]dale, that is a lot of LEDs. It was my understanding that 1 per 12 square inches of surface could grow anything and for LPS and softies it was more like 1 per 15 to 20 square inches. You are at 1 per 10 with that setup. I would be careful with the optics in the beginning. You are likely to melt any softies and possibly LPS if you go full bore. I would try no optics to start and then add according to need. Again, its my understanding that you want to be able to drive the LEDs at a decent clip to keep the temps in normal operating range whatever that is. If you use optics too strong you wont be able to turn them up. Just a thought form a fellow DIY'r. I went with the HLG 100 & 120 on my build with 4 strings on the blue driver and 2 strings on the white driver. No optics and the LEDs at 12 inches off the tank. Love them![/QUOTE] I hear you. I posted above - I think I am going with no optics to start, I will take others advice and once I get all my livstock setup, I will add specific optics where/as I need them. I know it seems like a lot of LEDs but being that the tank is 36" wide, I had to add at least 1 additional rows of LEDs to my design (32 LEDs) to be sure I could get front to back coverage, I added 2 rows (64 LEDs) to be safe. Also, I can hang this as high as 2 feet with no problems. So for a standard 180 tank (72x24) most people are in the 140 to 180 LED range, if you add in the adddtional 64 I would be at 208 to 248. So yah, maybe I have some extra LEDs! As my wife always says, bigger is better I will just ramp them up to where they need to be and then setup the apex and let em grow. I figure I if I only run them at 400 - 600 mA then that is less stress on the LED and the drivers will not be close to maxing out either. I would rather dial them down than have to re-do the thing and add more LEDs later.