LED question

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BSharrow

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Hi so I've been reading a bit about lighting with LEDs but I'm having trouble finding information on how many LEDs I actually need. I have a standard 90 gallon tank with soft corals,  but if it's in my budget I'd like to be able to keep some hard corals under them.

Thanks!
 
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xxmurrxx

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If you check out rapid led, shoot them an email with that question they will be able to tell you exactly how many would work.
So many is supposed to be equivlent to a 250w MH.  Don't remember off the top of my head though.
 
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Herwrasser

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Go with the cree 3W RB and NW. Its roughly 3W/gallon. Here is a link about the ratio and some recommended drivers. LEDgroupbuy.com is a good site or rapidled.com
http://www.nano-reef.com/forums/index.php?showtopic=284727&hl=captain+hook

"The ratio most people are going with is 2:1 RB (Royal Blue) to NW (natural white). You can add a Blue in that mix (2:1:1) RB:NW:B (regular blue) but you would be keeping the Blue at a low current. The blue will make your reds really pop."
 
Quartapound

Quartapound

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RAPIDLED is having a sale.... I just bought mine but am considering buying more, for the price.... only today (Black Friday)... 15-20 percent off!!  wish I had waited to place my first order!!
 
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BSharrow

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Thanks everyone, very helpful! So it looks like I need 48. Is there an HUGE difference between the Cree lights, and everything else?
 
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Blob-79

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We shall soon see. A bunch of us just ordered bulk amounts of 3w Bridgelux LEDs. Im sure there will be a few build threads regarding the leds coming up shortly. They are a little less powerful as the cree, but at a fraction of the price....so you can definitly afford putting in more LEDs.
 
Neopimp

Neopimp

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Crees are the most efficient ... most lumens per watt i guess.. BUT that is being debated as Cree now supplies the bridglux with the actual leds they sell... Do they sell them an inferior product on purpose.. who knows :)

For all we know they could be exactly hte same and have fallen victim to online forums that will this is better than that being its 1% brighter or something.  Like Blob said... we shall see..

My LED build inthe DIY section used crees.  They are way underpowered( I coudl increase hte ampeage they run at by 30 - 50%) and running with out optics.  I do not have any SPS to Test them with though. 

I am a believer of the "You get what you pay for". 

:)
 
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BSharrow

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I look forward to seeing the build threads then!

So as far as heat sinks go, I'm seeing some people are ordering from heat sink USA and some people are using aluminum channels. Are people making these channels or are they a re-purposed building material?
 
TORX

TORX

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I am re-purposed building material.

LED's are supposed to be delivered TODAY! Going on my lunch to Home Depot to pick up the channels and needed material. For a cooling system, I have a used computer power source and cooling fans which will be used for any cooling needed for the set up whether it be lights, ventilation or a chiller.
 
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Blob-79

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The aluminum channel can be bought many places, most steel supliers, princess auto...places like that. The channel is bought in the shape of a U. Just like how you may order some "I" beam, or round bar.
 
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Zakk

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The fan kit from rapidLED allowed me to use any pc fans, and they are 'dimmable', I just adjusted until the heatsinks were cool to the touch...just fyi :)

If you guys are using home depot bulk aluminum be -sure- to use fans.  Even on a big heatsink, these lights were able to de-solder themselves from their wiring in a few places.  Without the fans, these run HOT (well the CREE ones anyway).
 
Quartapound

Quartapound

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Zakk link said:
The fan kit from rapidLED allowed me to use any pc fans, and they are 'dimmable', I just adjusted until the heatsinks were cool to the touch...just fyi :)

If you guys are using home depot bulk aluminum be -sure- to use fans.  Even on a big heatsink, these lights were able to de-solder themselves from their wiring in a few places.  Without the fans, these run HOT (well the CREE ones anyway).
Click to expand...

What is your definition of hot?  I have 28 cree's on U channel, divided between 6x12inch U channel strips  (1"wide by 3/4" fins) with only passive cooling, driving at 710mA, and it doesnt get very hot at all.  The strips are spaced out evenly across 16", so there are gaps between each U channel.  I'll post pictures if anyone wants.  I used a Fluke multimeter with temperature recording feature to determine peak temps after 6 hours of runtime at max amp draw to determine my temperatures....

max I've seen is 20-30deg above ambient room temps.  Seemed like the large heatsinks with fans were overkill, IMO. 
 
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Zakk

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Are you using crees?

I have 12 LED's on a 4.25" X 9" heatsink:
9_inch_12_led_large.jpg

And I'm talking "hot enough to desolder, WAY too hot to touch."  I have 6 of those panels and all of them were egg-frying hot.

The actinic strips were on 1"X 18" sinks
thin_heatsink_large.jpg


and for whatever reason they run cooler.  Different drivers mind you, and all royal blue LED's.  Maybe it's the white ones that really cook. 
 
Quartapound

Quartapound

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Location
Kitchener, Ontario
fWMsM.jpg

9fsxj.jpg


I'm running 28 cree LED's.... 10 Cool White XP-G, and 18 Royal Blue XP-E.

14 per driver, in series, on meanwell drivers, at 710mA

they run very cool.  i can stick my finger right inside the C channel (direct contact with all 3 sides), it only feels warm.

strange how we have such different results.

I don't have  a finished hood/light deflector made for it yet, or a splash shield in place...
 
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Zakk

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Must be the ratio of blue to white, sames led's probably similar drivers (I even have the voltage dialed back).  Maybe because I have 12 per driver? Who knows, looks good though, and I'd rather have them running a lot cooler.  Hmm, do you have the optic lenses?  I wonder if that holds the heat in, as mine all have 60 deg optic lenses on them.. ?
 
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BSharrow

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So I'm looking at using an aluminum channel for a heat sink. Does the thickness matter?
 
Quartapound

Quartapound

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I got mine at home depot,  window and door department, 1 inch wide, 3/4 inch fins, 8 ft long.  14$ if I remember correctly.  I can check the thickness when home,

Sent from my Android using Tapatalk
 
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