[Nexgen]

First a little back story. I am building a light for my 40B using 5000k vero 18's and a combination of 3w leds for supplemental coloring. Each vero will have the 3w leds surrounding it, in sort of a cob style. The tank will be a dutch style tank, so I am aiming for very high light. I will not be running the lights at a level that creates high par levels but I want to over light then dim down to meet my needs, which will probably be more into medium lighting. I want to be able to make the colors of my fauna, celebs rainbows and probably cherry red shrimp, pop while getting good coloration out of my plant selection. So onto the questions:
1. What colors should I select for my 3w leds. Obviously deep red and royal blue are very common additions, but what else would you add. I have started to see more violets in planted fixtures. Is this a good addition? I have 6 channels of dimming for the 3w leds, channel 1 will be royal blue and channel 2 will be deep red, help me fill the last 4 channels.
2. Is it worth the extra $4 per led to get 5600k vero's or should the 5000k's be fine? 600k isn't much so I'm assuming no?
3. How many clusters of 1 vero and one of each 3w led should I use? I was thinking 4 in a zig-zag formation, but I'm open to opinions.
4. Should I use optics? With 120 deg beam angles if my calculations are correct at 16" from the substrate I should have a coverage are of a 27" radius circle. With 90 deg optics I will be at a 16" radius circle. Obviously the center will have higher par than the the outer edge.
5. Related to the optics question; how high should I hang the light, it will be in a canopy so anything from 1", from the rim, to 10" I can do?
6. I was planning on mounting the clusters on a 6" x 6" heatsink, here. Should this be enough to cool the clusters, with a 120mm fan and open top canopy?
I want to be able customize the way the tank looks and find what produces good growth while still looking good, hence the desire for many colors of leds. FYI, I am an electrical engineer student and I understand that different colors have different voltage requirements. I will address that issue once I have the colors picked out. This build was inspired by Fissure's build for his tank, so if anyone needs a visual of what I mean by a cob style of mounting the leds check out this thread.
Thanks, Brian

 

[jeffkrol]

cyan and violet are colors in short supply w/ most white Led's....
A visual brightener LED is lime..

w/ the 40b the calculations at the surface cones is what is realty more of an, arguable, issue..
So w/ roughly "single row" LEDs you want 20's somewhere near the diameter of the tank f/b
18" = 9" radius.. So 90's should be 9" from the water line.

I'd consider the Vero Decor line w/ 3 sets of :
Décor Food Vero 18 BXRC-25E4000-F-24
2500 80 1050 3242 2915 28.8 30.2 107

Décor Specialty Vero 18
BXRC-56G4000-F-24 5600 90 1050 3407 2998 28.8 30.2 113

Skip the colors unless you want a "specialty" glow, like blue "moonlight" or deep red sunrise.. ect..

Vero Decos have a "shot" more of cyan than most whites. Still short of violet though..

I have a hard time seeing 4 as being a good distribution amount. But 6 is way overkill......

ww decor pictured:

http://www.plantedtank.net/forums/20-diy/661818-diy-bridgelux-vero-18-led-build-3.html

 

[Nexgen]

Ok so let me make sure I understand you correctly. I would be fine running no optics, and have a 120 deg beam angle, if I had the light essentially at the surface of the water. And you say 4 is more than enough so could I get away with 3 evenly spaced across the center of the tank, and still have more than enough light.
And for supplemental lighting I should add some violet but other than that the décor vero's have a good spectrum for plants and visual. And adding some Royal blue would be good for moonlighting which I wanted to have. And then I could add some red and amber for good sunrise/sunset effects.
Finally I don't know how good you are with thermodynamics but would 3 of those 6 inch heatsinks, that I pointed out in my previous post, be enough to cool these lights.

 

[jeffkrol]

Wel, first I suggested pairing warm white/cool white Veros.. You "technically" wouldn't need any other colors if you want to accept 2500k sunrise..
violets/cyan could be added to fill the spectrum "holes" but most of the rest is fairly colored.. See 650nm peak in the vero DECOR (very specific phosphors in a very specific model to achieve a high CRI index rating) warm white..
Thermodynamics can really never be estimated and keep in mind "if" you went w/ the suggested 3 pair, you will probably run at such a reduced power that heating will be minimal..

120 degree optics spread 1.73 radius per inch above the water line..Keep in mind that light falloff is NOT even across the cone so as you near the edge intensity drops..Best way to think about it is a 120 degree cone has a real area of a 90-ish degree cone, which means for really good coverage t/b f/b consider 1" above 1" radius (2" diameter..).
Putting the diodes 9" above the water line will guarantee bright coverage from t/bottom.. Adj. as desired ..

Again 6 vero 18's IS overkill, but fairly cost effective..averaging 3000 lumens/chip @1A drive current.. 6= 18000 lumens over a 40b.. ...
4 t5 equiv on the visual lumen scale...........

 

[Nexgen]

Wel, first I suggested pairing warm white/cool white Veros.. You "technically" wouldn't need any other colors if you want to accept 2500k sunrise..
violets/cyan could be added to fill the spectrum "holes" but most of the rest is fairly colored.. See 650nm peak in the vero DECOR (very specific phosphors in a very specific model to achieve a high CRI index rating) warm white..
Thermodynamics can really never be estimated and keep in mind "if" you went w/ the suggested 3 pair, you will probably run at such a reduced power that heating will be minimal..

120 degree optics spread 1.73 radius per inch above the water line..Keep in mind that light falloff is NOT even across the cone so as you near the edge intensity drops..Best way to think about it is a 120 degree cone has a real area of a 90-ish degree cone, which means for really good coverage t/b f/b consider 1" above 1" radius (2" diameter..).
Putting the diodes 9" above the water line will guarantee bright coverage from t/bottom.. Adj. as desired ..

Again 6 vero 18's IS overkill, but fairly cost effective..averaging 3000 lumens/chip @1A drive current.. 6= 18000 lumens over a 40b.. ...
4 t5 equiv on the visual lumen scale...........

Ok, I'll do the 6 vero's, 3 of each, mounted on the heatsink I mentioned, but one that is 24"x6" since I won't need the full 36" of the tank. And probably add 3 royal blues, from steve's since they are like $1.40 each, for moonlighting and 3? violets to fill in the void that is missing from the vero's.

 

[jeffkrol]

Ok, I'll do the 6 vero's, 3 of each, mounted on the heatsink I mentioned, but one that is 24"x6" since I won't need the full 36" of the tank. And probably add 3 royal blues, from steve's since they are like $1.40 each, for moonlighting and 3? violets to fill in the void that is missing from the vero's.

Your choice.. but then might as well throw in cyan to fill the "gap" at 475k.

As a suggestion "3 up" leds w/ violet/cyan and 660nm red comes to mind but that is a suggestion based on a dislike of blue moonlight..
There are other options..

http://www.plantedtank.net/forums/10-lighting/870778-recommend-light-37-gallon.html

 

[Nexgen]

Your choice.. but then might as well throw in cyan to fill the "gap" at 475k.

Ok, here is what I got. I'm going to leave the violet and cyan out, for now. Might add them in later if I feel its lacking something, which I probably won't since on my current tanks I use cfl's and t8's.
I will probably not do a dedicated build log since there already is basically the same thing in gus's build, but I will include it in the tank build log.

 

[jeffkrol]

Ok, here is what I got. I'm going to leave the violet and cyan out, for now. Might add them in later if I feel its lacking something, which I probably won't since on my current tanks I use cfl's and t8's.
I will probably not do a dedicated build log since there already is basically the same thing in gus's build, but I will include it in the tank build log.

sounds like a plan..

 

[Nexgen]

sounds like a plan..

Just as a FYI for you Jeff or anyone else that reads this thread. The 5600k Decor Series Vero 18's are on back-order from digikey until April 16th.

 

[jeffkrol]

Just as a FYI for you Jeff or anyone else that reads this thread. The 5600k Decor Series Vero 18's are on back-order from digikey until April 16th.

The low K ones are the more crucial Decors..