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pdelcast
06/25/2008, 11:40 AM
Thought I would share with everyone my LED lighting project and progress on it.

Here is the basic LED light bar (8 light bars in this array):
<a href="http://s37.photobucket.com/albums/e92/pdelcast/?action=view&current=IMG00061.jpg" target="_blank"><img src="http://i37.photobucket.com/albums/e92/pdelcast/IMG00061.jpg" border="0" alt="LED Panel"></a>

Completed panels (from pick and place robot)
<a href="http://s37.photobucket.com/albums/e92/pdelcast/?action=view&current=IMG00060.jpg" target="_blank"><img src="http://i37.photobucket.com/albums/e92/pdelcast/IMG00060.jpg" border="0" alt="more LED circuits"></a>

Closeup of a panel
http://i37.photobucket.com/albums/e92/pdelcast/IMG00062.jpg

(sorry for the fuzziness -- these were taken with a cell phone camera)

There are 8 light bars on each panel, and they are scored to remove each circuit from the panel. Each bar has 12 x 3.5 watt LEDs, for a total of 42 watts per bar. The bars are 11" long. The circuit boards are made from aluminum to allow for good cooling.

Here is a closeup of an LED bar mounted on a heat sink (required for high power operation.)

<a href="http://s37.photobucket.com/albums/e92/pdelcast/?action=view&current=IMG00063.jpg" target="_blank"><img src="http://i37.photobucket.com/albums/e92/pdelcast/IMG00063.jpg" border="0" alt="LED bar on heatsink"></a>

pdelcast
06/25/2008, 11:45 AM
And finally:

4 bars in operation. Note there is a mix of 450nm blue and Cool White (8000K) LEDs on these bars. This is 168 watts of lighting in a 22" x 3" space.

<a href="http://s37.photobucket.com/albums/e92/pdelcast/?action=view&current=IMG00065.jpg" target="_blank"><img src="http://i37.photobucket.com/albums/e92/pdelcast/IMG00065.jpg" border="0" alt="LED bar lit (2)"></a>



For my personal project (90 gallon tank) I will be using 16 bars on 2 48" x 3" heat sinks with 4 x 60mm fans on each heat sink (bit of an overkill on the fans, but LEDs NEED to stay cool.)

Total lighting will be 672 watts, with similar efficiency to T5 bulbs (the white LEDs are 90 lumens/watt, and the blue are 345milliwatt light power output) but with a MUCH smaller footprint than the T5s.

We have 4 tanks total (3 personal tanks, 1 tank here at work) that we will be converting to LED lighting in the next few weeks.

BeanAnimal
06/25/2008, 12:04 PM
Nice work.. Don't we all wish we had a pick and place machine sitting beside a nice reflow or wave soldering station. I would love to design more using SMT instead of through hole!

Is the a commercial venture or just a side project using the resources at your disposal?

pdelcast
06/25/2008, 12:12 PM
<a href=showthread.php?s=&postid=12819453#post12819453 target=_blank>Originally posted</a> by BeanAnimal
Nice work.. Don't we all wish we had a pick and place machine sitting beside a nice reflow or wave soldering station. I would love to design more using SMT instead of through hole!

Is the a commercial venture or just a side project using the resources at your disposal?

Thanx!

This started out as a side project, but looks like it will become a commercial venture.


It is nice to have the pick and place machines here to do things like this (this was an after-hours project for engineering here.) We have total capacity to pick about 50,000 parts per hour on our SMT line. :)

BeanAnimal
06/25/2008, 12:21 PM
care to stuff a few of my boards :D

pdelcast
06/25/2008, 12:31 PM
This is a picture of three different LED boards, one white, one blue, and one half blue/half white (sideways.)

There is also one of the LED boards turned upside-down, to show the aluminum substrate.

The white LEDs have a yellow tint from the phosphor -- the white LEDs are actually blue LEDs with a phosphor added to make white.

<a href="http://s37.photobucket.com/albums/e92/pdelcast/?action=view&current=IMG00066.jpg" target="_blank"><img src="http://i37.photobucket.com/albums/e92/pdelcast/IMG00066.jpg" border="0" alt="LED bars"></a>

pdelcast
06/25/2008, 12:33 PM
<a href=showthread.php?s=&postid=12819588#post12819588 target=_blank>Originally posted</a> by BeanAnimal
care to stuff a few of my boards :D

I wish -- we don't have enough capacity just to do our normal builds -- it's nuts. :)

kcress
06/25/2008, 02:05 PM
Looks like the LEDs are just soldered to a flat piece of aluminum no traces visible...

pdelcast
06/25/2008, 02:38 PM
<a href=showthread.php?s=&postid=12820331#post12820331 target=_blank>Originally posted</a> by kcress
Looks like the LEDs are just soldered to a flat piece of aluminum no traces visible...

The white solder mask really hides the traces well -- but they are there. It's a Thermagon single layer aluminum backed laminate.

MadTownMax
06/25/2008, 02:47 PM
Nice project! Any thoughts on if something like this could be retro-fitted into the hood of a biocube? (would the heat sinks be too tall to fit inside the hood?)

Whalehead9
06/25/2008, 04:38 PM
Whose LEDs are you using are how are you driving them?

pdelcast
06/25/2008, 05:38 PM
<a href=showthread.php?s=&postid=12821344#post12821344 target=_blank>Originally posted</a> by Whalehead9
Whose LEDs are you using are how are you driving them?

Those are Cree XRE LEDs, and are being driven by a constant current ballast of my own design.

pdelcast
06/25/2008, 07:46 PM
<a href=showthread.php?s=&postid=12820632#post12820632 target=_blank>Originally posted</a> by MadTownMax
Nice project! Any thoughts on if something like this could be retro-fitted into the hood of a biocube? (would the heat sinks be too tall to fit inside the hood?)

You wouldn't have to use heat sinks that are as tall as the ones I am using -- those are a bit of an overkill -- so it could be done as a retrofit.

A heat sink with a fan would be fairly small, maybe 12" long, 1" wide and .5" tall. The fan would be required to keep the LEDs from overheating (they cannot go over 70C without damage.)

MadTownMax
06/26/2008, 07:06 AM
That's very encouraging - I'd be very interested in a higher wattage system that wouldn't require extensive cooling fans and a chiller ! :D

Deathwish238
06/26/2008, 07:46 AM
So how many lumens does a reef need per gallon?

cbusreefer
06/26/2008, 08:17 AM
how long till you have pics of this over your tank?

pdelcast
06/26/2008, 09:43 AM
<a href=showthread.php?s=&postid=12825098#post12825098 target=_blank>Originally posted</a> by Deathwish238
So how many lumens does a reef need per gallon?

Well, I'm gonna use a PAR meter to determine how much light I actually need in my tank -- I'm afraid of killing everything first time I bring the system online (it will be almost 3 times brighter than my 8 tube T5HO system.) So I'm going to start it way above the tank and slowly lower it down over time.

Using my simple LUX meter, two bars of LEDs (about 84 watts) outputs as much light as a 250W MH (10000K) and as much TOTAL light as 2 x T5 HO 48".

I'll put up PAR measurements after I get it set up above my tank.

dantimdad
06/26/2008, 09:45 AM
So, the ultimate question:

When will these be available for purchase and how much will they cost?

:)

dantimdad

pdelcast
06/26/2008, 09:56 AM
<a href=showthread.php?s=&postid=12825226#post12825226 target=_blank>Originally posted</a> by cbusreefer
how long till you have pics of this over your tank?

Retrofit for 28 gallon:


<a href="http://s37.photobucket.com/albums/e92/pdelcast/?action=view&current=light_1.jpg" target="_blank"><img src="http://i37.photobucket.com/albums/e92/pdelcast/light_1.jpg" border="0" alt="retro1"></a>

Closeup showing wiring and fans:

<a href="http://s37.photobucket.com/albums/e92/pdelcast/?action=view&current=light_2.jpg" target="_blank"><img src="http://i37.photobucket.com/albums/e92/pdelcast/light_2.jpg" border="0" alt="retro2"></a>


In operation:

<a href="http://s37.photobucket.com/albums/e92/pdelcast/?action=view&current=Tank.jpg" target="_blank"><img src="http://i37.photobucket.com/albums/e92/pdelcast/Tank.jpg" border="0" alt="tank1"></a>



Note that this is on one of my engineer's tanks -- and the light change was too sudden (upgrade from 2 bulb T6 HO system), he (partially) bleached one of his Acroporas. So he's running it at 1/2 power now.

lth03
06/26/2008, 11:21 AM
Very bright LED system,I am really interest on them.Are they only white or do you make them actinic too?

reef_only
06/26/2008, 11:41 AM
This is interesting. I'm waiting for cost break down info. But I'm sure one thing that those LEDs will last very long time.

yousmellsfishy
06/26/2008, 12:02 PM
Is the brightness of the LEDs prone to fading? I have moonlights on my tanks that are about a year old and are only a mere fraction of the brightness they were when they were new. Here's a pic of what I'm talking about. These are the same LED's - new on the left and old on the right (as if you needed to be told:rolleyes: )

http://i210.photobucket.com/albums/bb188/tmulcrone/PICT0164.jpg

pdelcast
06/26/2008, 02:29 PM
<a href=showthread.php?s=&postid=12826396#post12826396 target=_blank>Originally posted</a> by lth03
Very bright LED system,I am really interest on them.Are they only white or do you make them actinic too?

These are available in 450nm blue, 470nm blue, and cool white (8000K)

The tank above is lighted with 1/2 450nm blue, and 1/2 cool white (8000K.)

pdelcast
06/26/2008, 02:33 PM
<a href=showthread.php?s=&postid=12826534#post12826534 target=_blank>Originally posted</a> by reef_only
This is interesting. I'm waiting for cost break down info. But I'm sure one thing that those LEDs will last very long time.


Well, for this project it was VERY expensive. The LEDs are about $4-$5 each, the circuit boards for LEDs about $2000.00 total (or about $12.00 each) Parts and circuit boards for the ballasts were in the $1000.00 range. Machine tooling was around $1000.00

As a commercial product, you could expect to pay about $4 a watt. The lifetime of the LEDs is about 50,000 - 75,000 hours, so the cost is reasonable given the lifetime.

pdelcast
06/26/2008, 02:36 PM
<a href=showthread.php?s=&postid=12826653#post12826653 target=_blank>Originally posted</a> by yousmellsfishy
[B]Is the brightness of the LEDs prone to fading? I have moonlights on my tanks that are about a year old and are only a mere fraction of the brightness they were when they were new. Here's a pic of what I'm talking about. These are the same LED's - new on the left and old on the right (as if you needed to be told:rolleyes: )


Usually LEDs do not dim significantly over time -- your LEDs are either getting too hot or they are being over-driven.

If they get over 120C junction temperature, they dim REALLY fast, and the dimming is permanent. So, to keep LEDs alive for long periods of time, most manufacturers recommend that you keep the LED as cool as possible.

pdelcast
06/27/2008, 11:08 AM
<a href=showthread.php?s=&postid=12826396#post12826396 target=_blank>Originally posted</a> by lth03
Very bright LED system,I am really interest on them.Are they only white or do you make them actinic too?


Im' looking into even shorter wavelength -- maybe a 420nm or 400nm LED, but it is not a stock item.

reef_only
06/27/2008, 03:50 PM
This is promising, it has many side advantages and benefit for the long run. Has Solaris been making and selling something similar?

neuwave
06/27/2008, 04:36 PM
Hi you guys may want to check out nano-reef.com This guy and a few other guys like myself have begun our own projects or research with high power leds at a bit cheaper prices. Especially taking into accountwavelength, lumen production, and construction the circuts and more.

http://www.nano-reef.com/forums/index.php?showtopic=134394&hl=
http://www.nano-reef.com/forums/index.php?showtopic=138608

neuwave
06/27/2008, 04:37 PM
Sorry wrong links these should be right.
LINK (http://www.nano-reef.com/forums/index.php?showtopic=134394&hl=)

pdelcast
06/27/2008, 04:43 PM
<a href=showthread.php?s=&postid=12835509#post12835509 target=_blank>Originally posted</a> by neuwave
Sorry wrong links these should be right.
LINK (http://www.reefcentral.com/forums/index.php?showtopic=134394&hl=)

Are you getting LEDs at less than $1.00 a watt? That's about what I'm paying right now.

Of course I am using Cree LEDs, which are fairly expensive --- but they are also VERY high in lumen/watt. (what I'm using is about 90 lumen/watt.

You link is still broken -- please try again. I'm interested in seeing what others are doing.

easttn
06/27/2008, 09:25 PM
Patrick,
Your LED bars look very nice and similar to something I built in a past life.

We supplied US-LED with 500K+ (?) of these things for comerical track lighting. Your customer is using the same basic design; same physical size, voltage and current requirements, but a different LED supplier.

We used LumiLed back in 2003 -5 because it was a customer requirement. At that time we were beta testing CREE; glad they made it to production volumes.

Your thread has me asking a couple of questions.

There are 8 light bars on each panel, and they are scored to remove each circuit from the panel. Each bar has 12 x 3.5 watt LEDs, for a total of 42 watts per bar. The bars are 11" long. The circuit boards are made from aluminum to allow for good cooling.

Your bar(s) have 6 "cool white" LEDs, and 6 450nm blue LEDs; therefore you only have 21W/bar, or 84W/array. The royal blues are not additive. The numbers you are giving are also very dependant on Cree's capability to deliver the LED brightness you are paying for.

The MCPBS (metal clad printed circuit board) are sufficient for heat dissipation in our application as we require substantial airflow in the canopy; the heatsink is not necessary for 3.5W LEDs. If your customer is requiring additional thermal management, I'd review the contractual agreements.

Well, I'm gonna use a PAR meter to determine how much light I actually need in my tank -- I'm afraid of killing everything first time I bring the system online (it will be almost 3 times brighter than my 8 tube T5HO system.) So I'm going to start it way above the tank and slowly lower it down over time.

These LEDs will not be that bright as they are point source. They will not not kill your tank. If you have SPS, they will not do well. If you have LPS I have no idea as these were not my obsession.

If you are promoting this as a project then I think it is very important to explain the LED binning situation to the folks reading this thread. Cree (and all other manufacter) have an inability to predict the exact chromaticity (color), luminous flux (brightness), and Vf (voltage drop) of each LED prior to the production process. Therefore, they must test and bin every LED they make and provide a matrix of how to purchase their products. Here (http://www.cree.com/Products/pdf/XLamp7090XR-E_B&L.pdf) is Cree's binning. You may not see the difference, but over time the LEDs will self destruct if they do not have the same Vf in parallell paths.

If you are a manufacturer, send a PM. I can give you some "things to avoid" as you engage your contract manufacturing organization.

It is nice to have the pick and place machines here to do things like this (this was an after-hours project for engineering here.) We have total capacity to pick about 50,000 parts per hour on our SMT line.

This is not a slam. We had quite a bit more capacity wrt chip-shooters on 12 SMT lines. I'm really trying to help, just ask the folks I sent LED arrays to in the past. ;)

BeanAnimal
06/27/2008, 10:12 PM
You mean like the the one that lights up my soldering vice on my electronics bench or the handful of discrete packages that I started (but never finished) to put into my flashlight project?

easttn
06/27/2008, 10:30 PM
Maybe - troublemaker. ;)

pdelcast
06/28/2008, 10:03 AM
<a href=showthread.php?s=&postid=12837212#post12837212 target=_blank>Originally posted</a> by easttn
[/B]Patrick,
Your LED bars look very nice and similar to something I built in a past life.

We supplied US-LED with 500K+ (?) of these things for comerical track lighting. Your customer is using the same basic design; same physical size, voltage and current requirements, but a different LED supplier.

We used LumiLed back in 2003 -5 because it was a customer requirement. At that time we were beta testing CREE; glad they made it to production volumes.

Your thread has me asking a couple of questions.


Your bar(s) have 6 "cool white" LEDs, and 6 450nm blue LEDs; therefore you only have 21W/bar, or 84W/array. The royal blues are not additive. The numbers you are giving are also very dependant on Cree's capability to deliver the LED brightness you are paying for.

The brightness is a guaranteed minimum from Cree -- they are binned out (sorted) to meet criteria.

I guess I don't really understand why you think blue LEDs don't use any electricity? I'm not talking watts of brightness, I'm talking ELECTRICAL watts -- each LED uses 1 AMP forward current, and 3.65 volts of forward voltage. That's 3.65 watts per LED, and it doesn't matter what color they are...

Also, there are bars with 12 Whites, bars with 12 Blues, bars with 8 blues and 4 whites, bars with 8 whites and 4 blues, etc. They all draw about 42 watts of power.


Watts are not a measure of brightness, it is a measure of electrical power usage.
Lumens and PAR are brightness measurements. Blue LEDs don't add many lumens, but who cares about lumens? PAR is what matters (photosynthetic available radiation) and blue LEDs add more PAR than whites...

If you were doing this 5 years ago, it seems correct that your ideas of brightness are way off -- LED brightness has increased almost 20 fold in the last 5 years. If you tried using something like this for track lighting, you would blind anyone who looked at the lights. :) (These LEDs are not considered eye safe -- you cannot stare directly into the beam from the LED -- it can cause eye damage.)

Maybe you were thinking 3.5 Lumen output LEDs, and not 3.5 Watt LEDs? Then your post makes more sense. BTW, these LEDs output 336 Lumens each. (BUT they have a tight beam angle, so the brightness is VERY VERY high.)
<a href=showthread.php?s=&postid=12837212#post12837212 target=_blank>Originally posted</a> by easttn
The MCPBS (metal clad printed circuit board) are sufficient for heat dissipation in our application as we require substantial airflow in the canopy; the heatsink is not necessary for 3.5W LEDs. If your customer is requiring additional thermal management, I'd review the contractual agreements.


Again, you have me thinking you were using 3.5 lumen, and not 3.5 watt LEDs. You can't dissipate that much waste heat on the aluminum PCB alone, and keep junction temps reasonable (at least not in the density we are running.) With the heat sink pictured (THE BIG ONE!) and no additional air flow, the LED junction temps stabilize at about 65C. We wanted to be sure that the LEDs would get sufficient cooling to keep the junctions below 70C if all fans and forced air cooling failed. Anything above 70C, and you compromise the lifetime of the LED.
(edit - I just did the math - - with convection cooling only, and no additional heat sink, the MC circuit board would temperature stabilize at 205C -- WAY too hot for the LEDs.)

Our main designs are for high power motor control -- and we are very good at thermal management. I've done both the simulations and the lab work -- that is really the minimum heatsink for LEDs at that density with no airflow.

<a href=showthread.php?s=&postid=12837212#post12837212 target=_blank>Originally posted</a> by easttn
These LEDs will not be that bright as they are point source. They will not not kill your tank. If you have SPS, they will not do well. If you have LPS I have no idea as these were not my obsession.


Under a PAR meter, at 18"depth, four of these light bars are brighter in PAR than a 400W Metal Halide. This from an independent testing lab, got the PAR results yesterday afternoon.

This explains why we were bleaching SPS corals that were previously under T5 lighting. It wasn't a little too much light, it was WAY TOO MUCH LIGHT for an SPS that was acclimated to T5 lighting.
We are achieving greater than sunlight intensity on some of our setups. Did you look at the pictures of the lighted 28 gallon tank?

<a href=showthread.php?s=&postid=12837212#post12837212 target=_blank>Originally posted</a> by easttn

If you are promoting this as a project then I think it is very important to explain the LED binning situation to the folks reading this thread. Cree (and all other manufacter) have an inability to predict the exact chromaticity (color), luminous flux (brightness), and Vf (voltage drop) of each LED prior to the production process. Therefore, they must test and bin every LED they make and provide a matrix of how to purchase their products. Here (http://www.cree.com/Products/pdf/XLamp7090XR-E_B&L.pdf) is Cree's binning. You may not see the difference, but over time the LEDs will self destruct if they do not have the same Vf in parallell paths.

That's why we aren't paralleling any LEDs. Bad idea. Each LED string has it's own current regulated power supply. As far as binning, we buy LEDs binned for color and output. I'm not concerned about binning for Vf, because we aren't relying on Vf to control current -- we don't use any resistors for current control. Current control is fully closed-loop regulated for each string individually.

Oh, and don't let the binning confuse you. I've been trying to get Cree to get me LEDs from the outside bins, and they just don't have any -- The manufacturing process today is so well regulated that 95% of LEDs fall into two color bins, and three output power bins. There just isn't much fallout outside those few bins.
<a href=showthread.php?s=&postid=12837212#post12837212 target=_blank>Originally posted</a> by easttn
If you are a manufacturer, send a PM. I can give you some "things to avoid" as you engage your contract manufacturing organization.
This is not a slam. We had quite a bit more capacity wrt chip-shooters on 12 SMT lines. I'm really trying to help, just ask the folks I sent LED arrays to in the past. ;) [/B]

I appreciate your concern -- :) But I've been doing this for twenty years, eight years with my own company. This project was my own pet project (I have a 300 gallon tank coming, and didn't want MH on it.)

I have 1 SMT line with a quad chip shooters, with real-world 50,000 cph rate, and am quite proud that I've achieved that myself without any external financing. 50 full time employees, and about half are family. :)

pdelcast
06/28/2008, 10:19 AM
Spectrum of the LED bars from lab (All white LED bar -- using a spectroradiometer) The peak in yellow is typical for white LEDs..

Any experts want to give an opinion on the spectrum? (I'm interested in how the spectrum fits to use in a reef tank)


<a href="http://s37.photobucket.com/albums/e92/pdelcast/?action=view&current=led_08.jpg" target="_blank"><img src="http://i37.photobucket.com/albums/e92/pdelcast/led_08.jpg" border="0" alt="Photobucket"></a>

flyingclay
06/28/2008, 03:59 PM
cool ideas. Im interested in leds when the price is more reasonable.I have made leds for my tank to get more viewing time but it is not bright enough to grow corals or light the whole tank. looking forward the seeing more worrk done on LEDS, thanks

Rob_Zamites
07/03/2008, 07:26 PM
Another DIYer chiming in....I'm getting ready to do a DIY retrofit on my NanoWave 9 (actually, it's so butchered up now, I call it the 'Frankenwave') - 5 x Cree Q5's and 8 x Cree XL Blues, gonna drive it with 3 Buck Pucks. I'm very excited by the DIYer's taking on this new forefront in reef lighting!
Great work on the LED bars, those are kickass!

pdelcast
07/06/2008, 09:57 AM
Thank you for the kind words!

Work is progressing - - should have more pictures once I complete my 90 gal and 300 gal retrofit.

pdelcast
07/27/2008, 12:25 AM
OK: Here is the 300 gallon (new tank) lighting:

1150 watts -- 384 LEDs at about 3 watts each LED.


PAR measurements were done with an Apogee Instruments SQ-110 Quantum sensor connected to a Fluke 83 III digital multimeter.

Measurements were:

Above water surface (2.5" from LEDs): 3250 PAR
Just below water surface(4" from LEDs): 2200 PAR
5" below water surface (6.5" from LEDs): 1700 PAR
At top of rock shelf (about 17" deep) : 875 PAR
At surface of sand (about 28" deep) : 450 PAR

All PAR measurements are in umol*m-2*s-1



Edge on (beam pattern visible - 110 degree beam)

http://i37.photobucket.com/albums/e92/pdelcast/IMG_7631.jpg



Full tank view: (You can't see in this picture how bright this is)

http://i37.photobucket.com/albums/e92/pdelcast/IMG_7641.jpg



Room lighting totally washed out:

http://i37.photobucket.com/albums/e92/pdelcast/IMG_7642.jpg




Shot of the Apogee quantum meter and my Fluke meter:

http://i37.photobucket.com/albums/e92/pdelcast/IMG_7635.jpg




PAR reading at 5" below surface: (343mV - 1715 PAR)

http://i37.photobucket.com/albums/e92/pdelcast/IMG_7640.jpg

8BALL_99
07/27/2008, 01:13 AM
wow 450par on the sandbed. Thats crazy. I'm guessing this is directly under the fixture? How wide is the tank? How is it up by the glass on the front or back? It looks like it covers the tank pretty well.

pdelcast
07/27/2008, 01:28 AM
<a href=showthread.php?s=&postid=13030505#post13030505 target=_blank>Originally posted</a> by 8BALL_99
wow 450par on the sandbed. Thats crazy. I'm guessing this is directly under the fixture? How wide is the tank? How is it up by the glass on the front or back? It looks like it covers the tank pretty well.

It was about 290 PAR right by the back glass (shaded by the rock a little) and 350 PAR by the front glass, 450 PAR in the middle.

The tank is 96" wide, 24" front to back, and 32" high.

sditch
07/27/2008, 11:21 AM
<a href=showthread.php?s=&postid=12839211#post12839211 target=_blank>Originally posted</a> by pdelcast
Spectrum of the LED bars from lab (All white LED bar -- using a spectroradiometer) The peak in yellow is typical for white LEDs..

Any experts want to give an opinion on the spectrum? (I'm interested in how the spectrum fits to use in a reef tank)


<a href="http://s37.photobucket.com/albums/e92/pdelcast/?action=view&current=led_08.jpg" target="_blank"><img src="http://i37.photobucket.com/albums/e92/pdelcast/led_08.jpg" border="0" alt="Photobucket"></a>

Looks good, it would be nice to have a some good 420nm and have you spike more in the 440 range if you are looking to really make the corals pop. That may be hard to do as your higher spectrum is pretty high and would over power your lower spike.

pdelcast
07/27/2008, 06:22 PM
<a href=showthread.php?s=&postid=13031939#post13031939 target=_blank>Originally posted</a> by sditch
Looks good, it would be nice to have a some good 420nm and have you spike more in the 440 range if you are looking to really make the corals pop. That may be hard to do as your higher spectrum is pretty high and would over power your lower spike.

For the actual tank, I'm using 450nm (Royal Blue) LEDs along with the white LEDs -- so there is a much bigger blue spike centered around 450nm.

The whites are pumped with a 470nm blue -- that's why the big spike at 470 in the picture.

SO -- there is more power a little lower than shown in that picture.

sditch
07/28/2008, 05:13 PM
Looks like it would provide good growth.....keeep us posted.

maddog2002
03/11/2010, 07:35 PM
Any update for this?

easttn
03/11/2010, 08:42 PM
Love to see how this turned out. Still piddling.

wld1783
03/11/2010, 09:04 PM
Usually LEDs do not dim significantly over time -- your LEDs are either getting too hot or they are being over-driven.

If they get over 120C junction temperature, they dim REALLY fast, and the dimming is permanent. So, to keep LEDs alive for long periods of time, most manufacturers recommend that you keep the LED as cool as possible.

+1

Also the Cree LEDs rock much better than the LEDs 2 or 3 generations ago. But do keep them cool.


Bill