I'm thinking of building an LED fixture little by little and need help...

[STiTCH87]

I'm contemplating spending a little bit of money here and there and building my own LED lighting fixture, but need some help.

I have a 29g and want the LEDs to be bright enough to equivalent a good Metal Halide light in intensity, so that I may keep high light corals and clams if need be, but also plan on getting a dimmable driver for it as well, which hopefully I can control with my RKL.

I need to know what optics I should use, and how many LEDs I should put over a 29g to achieve the same PAR intensity as a MH fixture.

Also, I want it to be slightly on the bluer side of coloration, so I assume that means more blue LEDs than white? And is it hard to wire everything up in such a way as to have two power cords?

 

[PasstheTorch]

On a 29 from what I've read something like 60 or 80 degree would be the best and to me the rapid led kits would be the best. They have a 24 led kit with all that you would need. IMO 24 led's would be enough but other people chime in as well. And as the difficulty of wiring them it's pretty easy. Do the blue LEDs on one string and the whites on another. Wire plus to minus the hole way until you get to the driver. And your would want to do 2 heatsinks with 12 on each. Like 6 whites and 6 blues on one and the same on the other. I'm pretty new to led's but this is my understanding on the basics of them. I hope I helped. ( expert reefers post with corrections if I messed something up or forgot to mention something )

 

[PasstheTorch]

And if you want more blue then white do like 8 blues to 4 whites on each heatsink. That would give u a more 20,000 k look IMO

 

[STiTCH87]

yeah I was actually looking at the 24 kit at rapidLED

Whats better, cree or the q5? I figure the q5 cuz its in the deluxe kit and costs more, but idk anything about leds so someone please chime in.

They say 24 LEDs mimics a 150w MH. is a 150mh what people would use on a 29? cuz I could always go with more LEDs to mimic 175-200w MHs I suppose... but I dont wanna bleach anything.

They have a 70 optic. would that be good?

And how do you wire to a heatsink? I thought a heatsink was arctic silver glued onto a metal plating that an electric component is also mounted to?

 

[Cjtabares]

The optics you use will depend on how high you want to hang the fixture over your tank. The q5 is a Cree. Cree is the company name. And to figure out how many LEDs you are going to want to use it is more important to know how much space you want to cover and how high you want to hang the fixture. Irony know to much about LEDs but am also researching and talking to some BRS members trying to build my own LED fixture for my upcoming tank build.

 

[STiTCH87]

Well it's a standard dimensioned 29g, I want to equally light the whole thing, and the fixture will be about 4-6 inches above the tank. Probably more like 5".

 

[PasstheTorch]

You could do anywhere from 24 to 36 LEDs depending on what space you want to cover or the intensity your looking for. To me 36 would be slightly overkill as they are really powerful, but if your dimming them down then having the 36 might be nice for good shimmering coverage.

 

[DoctaQ]

24 should be enough leds, the kit from rapid should be enough, q5 is the bin number and is most commonly associated with the xr-e (slightly old but still enough for our needs) 70 deg optics and 24 leds sounds like a good plan. the heatsink is to draw heat away from the leds because heat shortens the lifespan of leds. it also serves to hold the leds and to space them. i would go with at least 2 ft of heatsink for the 30 inch tank. drilling and tapping is the best way to attach the leds, it provides the best thermal transfer and allows you to change the leds out easily if you want. thermal pads are fast and still have good enough thermal transfer for leds.
you can get the same number of leds and run the blues at a higher current than the white, the problem with getting more blues is that there might not be enough whites for coverage, which will give you white spotlights instead of an overall color, i consider 8-10 to be the absolute minumum of whites to cover the tank which means if you want 20k at the maximum led power (you will probably never need that much) then get 36 leds 24 rb and 12 whites.

if there is a center brace on the 29 then split it up into two heatsinks, otherwise a 24 inch single heatsink will be less trouble to mount.

a crazy extra idea, you could run a 24v power supply to run 6 extra blues and run two fans in series off of that, otherwise a 12v will let you run 2-3 leds and single fans in parallel.

running seperate cords for blues and whites will be easy, also to control with the rkl you will need the alc module which works perfectly with the meanwell eln 60 48d

 

[MrReefer]

24 should be enough leds, the kit from rapid should be enough, q5 is the bin number and is most commonly associated with the xr-e (slightly old but still enough for our needs) 70 deg optics and 24 leds sounds like a good plan. the heatsink is to draw heat away from the leds because heat shortens the lifespan of leds. it also serves to hold the leds and to space them. i would go with at least 2 ft of heatsink for the 30 inch tank. drilling and tapping is the best way to attach the leds, it provides the best thermal transfer and allows you to change the leds out easily if you want. thermal pads are fast and still have good enough thermal transfer for leds.
you can get the same number of leds and run the blues at a higher current than the white, the problem with getting more blues is that there might not be enough whites for coverage, which will give you white spotlights instead of an overall color, i consider 8-10 to be the absolute minumum of whites to cover the tank which means if you want 20k at the maximum led power (you will probably never need that much) then get 36 leds 24 rb and 12 whites.

if there is a center brace on the 29 then split it up into two heatsinks, otherwise a 24 inch single heatsink will be less trouble to mount.

a crazy extra idea, you could run a 24v power supply to run 6 extra blues and run two fans in series off of that, otherwise a 12v will let you run 2-3 leds and single fans in parallel.

running seperate cords for blues and whites will be easy, also to control with the rkl you will need the alc module which works perfectly with the meanwell eln 60 48d

Great info. I've seen members mix in a red LED too. Gives it a great pop and look in my opinion. Its personal preference and it's hard to really know how it looks like until you actually see it but it's pretty sick

 

[DoctaQ]

the only place ive used a red before was experimentally in a freshwater fixture for a planted where there was no shimmer but it didnt add much to the look surrounded by whites, you could see the red when a fish swam directly underneath. if there were shimmer as in a reef tank id imagine the red shimmer combined with blue and white would be very distracting

 

[STiTCH87]

Might experiment with a red. That was some VERY good info though! thanks! So on the fixture, can I wire in the fans so that they run on the same power cords as the lights? As in half the LEDs and 1 fan on one cord, and the same on the other cord? And would 24 LEDs get bright enough for high-light SPS and clams?

 

[STiTCH87]

So i'm thinking about replicating this fixture:

Complete with the individual heatsinks (opinions?)

But instead of horizontal heatsinks, I wanna go with the round ones for a convectional and more equivalent cooling.
Here's a pic:

 

[PasstheTorch]

Did you find a place that sells those small rectangular heatsink? I was looking for those but could not find them. They would be perfect for my nano. The circle heatsinks might be hard to mount to a fixture but that's just me guessing.

 

[STiTCH87]

Those were custom cut, but squares are inefficient anyways. The vertical circles are most efficient because they can convection cool. They're easy to mount too. But if space might be an issue than i'd suggest you use a standard heatsink plate. These are tiny though. About an inch tall which is the height of your average horizontal heatsink anyways. But by having it shaped in a circle, and vertical plates rather than horizontal, the heat can convection cool and be pulled away from the LED far more effectively. Read all about it. =] I think you could spray paint them too though IDK if that'd affect their effectiveness.

 

[DoctaQ]

i have a bunch of those little heatsinks, ive found that they can handle 700ma each easily, im testing aluminum U channel soon, its cheap

 

[DoctaQ]

the radial heatsink is very good, but kinda pricy i think

 

[STiTCH87]

I believe they were $1.75 each when I looked. I know they were under $2 each anyways.

 

[DoctaQ]

spray painting them will reduce thier effectiveness unless the paint is a metal echant

 

[Cheetos]

Just built a setup for my 125 using the aluminum U-channel. It works well for minimal amounts of LEDs but I'm not sure it would handle a lot of them unless you have some serious fans!

 

[DoctaQ]

im going to test some extra thick u channel tonight that i bought on ebay, i plan on putting about 20 watts through 3 ft