Need LED advice..don't know where to begin!

[iwishtofish]

I have a 15g (12 long x 24 wide) nano housing my corals now, while I wait to set up a 24x24x24 cube tank. I want to build LED fixtures for both (half now to cover the 15g, and the other half later - so both together can cover the cube tank).

I need some ideas. Can anyone point me to the best threads that cover dimmable LED building? And I'd love some ideas on these points:

* Where to get custom-size heat sinks (and how big do I need?)

* How many LEDs to use, and how many dimmable drivers would I need?

Thanks to anyone who has the time to comment!

[Stu Pickles]

rapidled.com

[iwishtofish]

rapidled.com

Been there...nicely, they are a club sponsor, too. It appeared that their widest heat sinks were only 6", and I think I need to go wider for a 12" wide (front to rear) tank, don't I?

[BigAl2007]

RapidLED

ReefLEDlights


ModularLED

I'm sure there are others but I've dealt with these specifically. ModularLED is where I got my custom set-up for my RSM130D and LOVE IT!!

[MarkGP]

For the heatsinks in any size you want.....http://heatsinkusa.com/
If you don't see the size listed give them a call. They will cut any size for you!

[iwishtofish]

RapidLED

ReefLEDlights


ModularLED

I'm sure there are others but I've dealt with these specifically. ModularLED is where I got my custom set-up for my RSM130D and LOVE IT!!

For the heatsinks in any size you want.....http://heatsinkusa.com/
If you don't see the size listed give them a call. They will cut any size for you!

Thank you both for the links!

[joelespinoza]

What kind of corals? How far down will they go in the tank? How deep will your sandbed be?

Basic rule of thumb is 1 3w LED per 15-20 square inches of surface area for tanks up to 24" deep. 1/15 is high light for sps and clams, and 1/20 is medium high for lps and would be fine for growing sps as long as they are high up in the tank.

That being said you have 24" x 24" surface area = 576 square inches, 576/15 = 38.4 LEDs, assuming you are looking for a high light setup and you want a 2:1 ratio split into 2 panels you would be looking at either 36 or 42 LEDs (since you want an even number divisible by 3).

Since you are right at 24" deep you may want to go for this higher 42 LED setup, although it does depend on the LEDs you get and how hard you drive them.

On the top of this page is a 42 LED build I laid out for someone else, other then the heatsink this would be perfect for your tank, also I have since started suggesting the 2700k Luxeon warm whites, they are just really amazing IMO:

http://www.reefcentral.com/forums/showthread.php?t=2179698&page=3

For a heatsink you could do 2 - 8.46" x 20" or 2 - 10" x 20" from heatsinkusa, I personally think huge heatsinks are way better in the long run since they can be run passively so they are cheaper and require less maintaince then small heatsinks with fans, but there are other options too.

[mids1999]

How does the basic rule of thumb for 3w apply to the Cree 5w LEDs, add ?% to the covered area?

[rovster]

If in your shoes, I'd do a Rapid kit for the smaller tank, then you'll have an idea of how to do it and make up your mind for the larger one. I have a Rapid kit and it was very easy to set up. Soldering is easier than you'd think. Talk to Mike. He's very helpful.

[jmn111080]

Rapid kit

[joelespinoza]

How does the basic rule of thumb for 3w apply to the Cree 5w LEDs, add ?% to the covered area?

That basic rule of thumb was for Cree XT-E and XP-G driven at a max of 700mA. Looking at the Cree XT-E Data sheet they consider 350mA to be the baseline 100% light output. It appears ~700mA to be about ~175% of the light output and ~1300mA to be about 275% of the light output. Considering they will get less efficient at higher temps its probably safe to say that on average, you would need 1.5x the XT-E LEDs driven at 700mA as you would with the same LEDs driven at 1300mA.

So the modified rule of thumb would look like this:

1 XT-E/XP-G Cree driven at 700mA per 15-20 square inches of surface area up to 24" deep

Or

1 XT-E/XP-G Cree driven at 1300mA per 22.5-30 square inches of surface area up to 24" deep

Or

1 Phillips Luxeon driven at 1000mA per 22.5-30 square inches of surface area up to 24" deep

As far as rapid LED goes they are not bad, I have delt with them and their products and customer service are acceptable but their prices on many things are kinda high. The reason I recommend stevesleds is that he is exceptional in customer service, products, and pricing.

The main advantage of going with rapidled is they have comforting kits, if you have no clue what you are doing you can order stuff from rapidled and have a working product when you are done. It may not be great, and if you just order the kit as it comes, without changing the colors or ratios, it certainly will look washed out and crappy, but it will be a functional light that grows corals.

[mids1999]

Thank you for doing the math.
+1 for Rapid LED.

[iwishtofish]

What kind of corals? How far down will they go in the tank? How deep will your sandbed be?

Basic rule of thumb is 1 3w LED per 15-20 square inches of surface area for tanks up to 24" deep. 1/15 is high light for sps and clams, and 1/20 is medium high for lps and would be fine for growing sps as long as they are high up in the tank.

That being said you have 24" x 24" surface area = 576 square inches, 576/15 = 38.4 LEDs, assuming you are looking for a high light setup and you want a 2:1 ratio split into 2 panels you would be looking at either 36 or 42 LEDs (since you want an even number divisible by 3).

Since you are right at 24" deep you may want to go for this higher 42 LED setup, although it does depend on the LEDs you get and how hard you drive them.

On the top of this page is a 42 LED build I laid out for someone else, other then the heatsink this would be perfect for your tank, also I have since started suggesting the 2700k Luxeon warm whites, they are just really amazing IMO:

http://www.reefcentral.com/forums/showthread.php?t=2179698&page=3

For a heatsink you could do 2 - 8.46" x 20" or 2 - 10" x 20" from heatsinkusa, I personally think huge heatsinks are way better in the long run since they can be run passively so they are cheaper and require less maintaince then small heatsinks with fans, but there are other options too.

Thanks so much for this amazing advice! When I get back to the real computer, I'll check the link and maybe ask you some more specifics, if I think of some. :)

[iwishtofish]

If in your shoes, I'd do a Rapid kit for the smaller tank, then you'll have an idea of how to do it and make up your mind for the larger one. I have a Rapid kit and it was very easy to set up. Soldering is easier than you'd think. Talk to Mike. He's very helpful.

Rapid kit

Maybe a good idea to do a trial run for the smaller tank? I guess I'd rather do that than piece two lights together when I set up the bigger cube.

[joelespinoza]

However you want to do it, LEDs work out great in modules. I have a bunch of little 2-6 LED modules each made up of a cpu cooler and old laptop power supply (or cell phone charger for the 2 LED units). They work out great on various 5-10 gallon glass top tanks and algae filters. For a while I even kept one in my girlfriends car to use as a worklight =).

Anyway if you have any questions or need help you can always PM me, I know what a pain all this is to figure out for the first time, especially while trying to save money and end up with a decent product. But it does get MUCH easier after the first one, I now setup the lighting for all my friends tanks.

[robn70]

Another option to look into would be the Kessil pendents. http://kessil.com/

[joelespinoza]

Heres the thing about LEDs, they easily produce enough power to drive photosynthesis, in fact the issue most commonly run into is not a lack of power, but too much.

The real issue with LEDs over T5HOs or Metal halides is asthetics, LEDs are often used in combination with T5s because typical LEDs kits by themselves make colors look "washed out", so here is something to think about:

CRI = color rendering index.

Warm whites = usually higher CRI, cool whites = usually lower CRI...

CREE XP-G Typical CRI for Cool White (5,000 K - 8,300 K CCT) is 70.

Phillips Luxeon 2700k Warm white from Stevesleds - CRI 95.

Yet people make LED lights with cool whites (like the kessils seem to use) and then wonder why their colors seem washed out.... Like the colors are not being rendered correctly..... Then they try to add all kinds of crazy light colors to try to get colors to render correctly after the fact, when the problem was they used the wrong color white LEDs to begin with.... Look around on this forum, I am sure there is more then a dozen threads running around here about LED asthetics...

[iwishtofish]

I kind of abandoned the idea for a while, but now I'm back reviewing the good advice I received so far. Thanks again to everyone.

I'm having trouble finding heat sinks wider than 6", though. I'd like to use one that is maybe 10" wide x 20" long. Does anyone know the ideal thickness and fin height?

[iwishtofish]

Ok, I see that HeatsinkUSA will cut 10" wide heat sinks to length. Hopefully I can find a less-expensive alternative. Drilled and tapped would be great. I wish Rapid LED sold them wider than 6".