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  #26  
Old 01/08/2008, 02:36 AM
badpacket badpacket is offline
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Gus, go to the Luxeon and Cree, Seoul websites and look at their technical suppport references. They have all the information you need.
The hard part if getting the constant current correct, and getting the proper heat sinks and LED's sinked to them.
Aside from that, its going to cost you $$ to experiment. If you have the excess cash, then go ahead, otherwise just spend $20 for a couple and play with them. If you can get them to run without burning up after a couple of weeks, then you are on your way.

While this is something that can be done by novices with electronics background, it is still subject to expensive error, and in many cases the expense is in reinventing the wheel that the manf's have already done.
  #27  
Old 01/08/2008, 08:26 AM
liveforphysics liveforphysics is offline
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You are way off on power supply cost. I'm driving my 30 Cree LEDs with a CC source I made with an old computer power supply for about $15.

My blue Cree LEDs were $4.85/per.

My white Cree LEDs were $8.25/per. I use this outdated model of LED by Cree. But I got a deal buying in quanity.

http://www.kaidomain.com/WEBUI/Produ...px?TranID=2663

I also use an optic just like this, except I got mine a little cheaper than $1 each.

http://www.kaidomain.com/WEBUI/Produ...px?TranID=1603

My 30 Cree LED project has been working for months now, and will continue to work for years with no maintence. I've got about $200 bucks into it. My tank has way too much bottom area (21 square feet) for it to provide enough light to do much on it's own, It's mostly blue and I use it as extra suppliment during day/night transitions. The project purpose was mainly just to see how I liked dealing with LEDs on my tank. Compaired with the 12HO T5 bulbs and the 4x MH also in the lighting setup, it's barely noticeable. However, its also barely noticeable if the 4x MH bulbs are on once the 12x T5 bulbs are lit. I have to bend down and peek.

Yes it can be done for relatively cheap. I did it, and I like it. If he were to experiment with driving LEDs and heat sinking and CC supplies, he could do it as well. Likely for under $600.
  #28  
Old 01/08/2008, 08:31 AM
liveforphysics liveforphysics is offline
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BTW- The big problem with LEDs has not even been mentioned.

The spectrum of 460nm is outside the range of absorbtion for chlorophyll A. It wants to see 410-420nm and 670nm. It gets no value from 460nm, which is what all efficent blue LEDs emmit.
  #29  
Old 01/08/2008, 11:59 AM
marinoob marinoob is offline
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gosh why cant led technology come along faster its seems like it could be so good
  #30  
Old 01/08/2008, 12:32 PM
Flybynight Flybynight is offline
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My tank is only 4 foot long not the normal 6 foot. It is much taller and deeper.
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  #31  
Old 01/08/2008, 12:38 PM
Flybynight Flybynight is offline
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Quote:
Originally posted by liveforphysics
BTW- The big problem with LEDs has not even been mentioned.

The spectrum of 460nm is outside the range of absorbtion for chlorophyll A. It wants to see 410-420nm and 670nm. It gets no value from 460nm, which is what all efficent blue LEDs emmit.
You are saying the Blue LEDS will not make photosynthesis happen? Does NM stand for Nano Meter?

Hey, I am learning so I am going to ask the stupid questions.
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  #32  
Old 01/09/2008, 10:57 PM
badpacket badpacket is offline
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liveforphysics, who is off on the psu costs?

Anyways, I don't think anyone is saying that the average electronics minded person can't sling something together like you have for a modest amount of money.
However in your own words it doesn't sound like it bought you very much in actual light, regardless of wavelength.
Too get something comparable to your T5/MH's, most of us know you'd have to probably double, triple, quadruple the number to start getting some meaningful light.
Just saw your tank, make that even more LED's.....

But, now I'm not sure what your point was or mine for that matter.
  #33  
Old 01/10/2008, 02:40 PM
big400g big400g is offline
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I just caught this thread, I have been working on a huge LED array for my 400 gal reef system. The led array is going to be 10 feet by 2.5 feet...

Anyways I am using the Luxeon LED's partially because they have the proper spectrum if specific led's are mixed in specific percentages (I have been working on this for about 1-2 years). As mentioned above some of the blue LED’s are the 470 NM which makes for a great moon light. I have not looked into the Cree LED's and am unfamiliar with the spectrum of them. It seems like Cree is making good advances and may give a better Lum/Watt.

I had a prototype built (I am working with Electrical Engineers to make this actually work) and it was only 8 Luxeon K2 LED's I put it into the tank hood with the other lights (175W MH and Actinic) on and I could see the area where the LED's were shining as it was visibly more light... I do not have a PAR meter but it looked brighter, I turned them off and on several times in different areas of the tank and I was able to have more light on the sand floor of my 72 Bow Front tank. The thing to remember is that LED's are much more of a direct point source light meaning that they shine directly down in the tank unlike MH and other lighting sources, this gives them a higher efficiency.

The reason I went this direction is that after the initial cost I will not have to deal with it for 4-5 years, I will spend less on electricity and have no cost for replacement bulbs twice per year. Additionally I will not have the heat issues of the MH bulbs.

Good luck on your project, keep asking questions and look at the company sites all of the information is available, it just takes time to figure out what will work best for you. As mentioned before you will need drivers for the LED's, if you go with something like the Buck Puck it will be cost prohibitive for large arrays. You will want to figure out how to create a Pulse Wave Modulated power supply for the LED's mine can drive something like 30 led's per power supply. This is where things become tricky and where my personal knowledge ends. The other thing to consider is how you will turn them on and off, will you dim the lights… I am running mine to slowly dim on and then off, everything is controlled from an Aqua controller.

I figure most people could figure out the wiring, heat sinks, and other items, but when it comes to creating the PWM controller and other aspects the average person will need help. I would work on finding someone who knows that stuff first, they will most likely be able to help you in the rest of it as well. I was surprised and very lucky to find the people I did, they are just like us here on RC willing to spend our time and sometimes money helping other fellow refers out. They are still in collage and willing to help me to learn more, they are spending my money to play with things that they could only imagine building otherwise and are talking about building it for me close to free… Yeah I am amazed and happy to say the least.

I hope that gives you some ideas, things to consider and help in your endeavors, I wish you the best of luck.

-Ryan
  #34  
Old 01/10/2008, 03:19 PM
Flybynight Flybynight is offline
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Good ideal about getting people who would want to help. I do the same kinda things with saltwater and corals for local people. How would I go about finding someone to do this project for me?


Maybe I could go to a local colage and talk to a teacher. Which would be realy easy to do because there is one less than a mile from where I live. ASU.

What is the cost going to be for your system? How many watts and so on?

Thanks for wishing me luck.
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  #35  
Old 01/10/2008, 03:41 PM
big400g big400g is offline
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Is it for the 120Gal Reef?? It is hard to say as most peoples needs are different. I will have SPS so I need strong light, if yours is similar I have 250 LED's giving me about 61 Lum per gallon. You may be able to get away with about 75-100 led's. I can not remember the wattage but it is allot. I think the cost will be about $2,500-3,500 plus the Aquacontroller 3 and other bits... Not cheap but compared with replacing about 15 lights at about $50 each for 5 years this ends up costing less AS LONG AS IT IS DESIGNED TO LAST 5 YEARS. This is the whole reason I am having someone who knows more than me put it together, I could not bear to spend $3K for one year of lighting...

I found the guys working at Frys believe it or not, they are trying to start a LED business... mine was just amazing luck! Yeah head to ASU and talk with students that are EE's and interested in LED's. Need lots of luck, or find a startup LED Company looking to start a project like this and it will cost you a bit more.
  #36  
Old 01/10/2008, 04:21 PM
Flybynight Flybynight is offline
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If you run your light 12 hours a day that is only 21,840 hours in 5 years. I would hope they last more like 10 years. that is still less than they say they should.

So you are saying that it will cost me 2 to 3k $ for my tank, or yours? I only run 2 250s on my tank and it does very well. I am out $1000 for 5 years. I could buy build my geothermal Chiller WAY cheaper than that Haha.

Bet no one has though about a Geothermal Chiller before hu? I have been thinking about if for a while. You shoule be able to chill your tank to 75* with just a small 300 or 400 GPH pump and some pipe. Anyway. sorry for getting off topic.
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  #37  
Old 01/10/2008, 04:54 PM
big400g big400g is offline
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Mine is about that cost... not sure what you have in yours, mine has a bit more light than is needed for fish with live rock.

2-250 watt bulbs replaced lets say every 6 months makes it so you have only 4 bulbs per year to replace, the cost is manageable. I would have many more lights to replace which makes this much more intriguing. You could be looking at about $1-2K for yours not sure where you buy the stuff, which ones you go with and how you drive them. There are more simple and possibly cheaper ways than what I am doing but with SPS this is the best way I could find. I hope to get closer to 7-10 years but am not sure if the spectrum will still be perfect at that time, plus if I plan on 5 years and get 7 I am happy and the project made sense. If the project made financial sense over a 10 year span and it only lasts 3-4 I would be very upset.

I say yours will cost $1-2K but you should be able to do it for less. The heat sink material can be a place to save some money depending on how you buy it, it can be a huge expense or not as bad. This will not be a cheap project for a large LED array like you are planning, plan for a larger cost and use the rest of the budget on beer or corals when the project comes in under budget.

I have seen a tank (on a forum) that used Geo thermal for both heating and cooling… Very cool idea, but the cost and hassle for me outweighs the benefit (concrete basement floor.)
  #38  
Old 01/11/2008, 07:05 AM
liveforphysics liveforphysics is offline
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Flybynight- I used a 20ft legnth of 3/8" titanium pipe bent into a large U-shape and burried about 7ft in the ground for cooling. Most all the comercial greenhouse coral farms use a similar method of using the earth for a heatsink. The only problem is you gotta keep at least 1-2 gallon per hour moving through it at all times. Otherwise, when it kicks on again and circulates that stagnant water back into your tank it smells so bad you would swear it is a sewer feed to your tank.

big400g- I don't know if you've allready bought your LEDs, but they make LEDs with 3-4 times the light output of the K2's from 2 years ago. That means you could go from 250 LEDs to 100ish, and still be making more light. Power draw would be cut by about 3-4 times as well.

Also, you can mix LEDs to get whatever color temp you desire, but you can't fix the spectrum problems of the LED.

All modern white LEDs are 460nm blue LEDs with thin phosphor flake positioned above the blue LED. The blue light stimulates florecence in the phosphor which emmits other longer wavelenghts of light. Since it is impossible to decrease wavelegnth during florecence, only increase it, those 460nm LEDs can never see the 410-430nm window that chloro A requries.

If you wana make an easy power supply, you can run strings of 45 LEDs in series, and use a single simple current control regulator straight from the 160VDC you get when you throw a rectifier and cap on the 110VAC stright out of the wall.

Also, just incase somebody was thinking of buying a bunch of them, buckpucks are a totally garbage product. They are like a last resort desperation thing if you just need to run a handful of LEDs and power efficiency doesn't matter.
  #39  
Old 01/11/2008, 07:17 AM
liveforphysics liveforphysics is offline
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If you wish to hit the desired wavelegnths, you can do it with "royal blue" LEDs. However, they operate at around 50% of the lumens/watt that something like a T5HO bulb does. Semi-defeats the point of the project.

I actually just bought $700 in LEDs and optics last night after thinking about this thread for a while... I'm going to play with aspheric projection lenses.

I wish to be able to mount my LED array flush on the ceiling, have nearly no light directly hitting the glass, and have no annoying glare from the lights when you are in the room. Aspheric projection lenses can make this happen. The downside is cost and labor... I just shelled out $700bones for the chance to just to play with them, and still it doesn't correct the spectrum... Fortunately I'm an LED addict, and I love combining my LED hobby with my aquarium hobby.

Best Wishes,
-Luke
  #40  
Old 01/11/2008, 11:00 AM
Flybynight Flybynight is offline
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How deep will the LEDs penetrate? I know M/H are good for about 3 or 4 feet.

Hey liveforphysics, Keep me updated.
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  #41  
Old 01/11/2008, 11:08 AM
liveforphysics liveforphysics is offline
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LED with an aspherical projector can reach 1million candle power. That would penatrate deeper than a 1,000watt large plasma chamber halide is able to do, unless it also has an aspherical projector.

If you wish to learn about lights, and LEDs in perticular, I recomend this forum.

www.candlepowerforums.com

If you do searches for the word "aspherical", the pics of the throw on these LEDs is insane. Like putting a bright spot on the side of a water tower at 1 mile away insane...

The only downside is that unless you can source them from some sort of used optics wholesaler, you will be paying around $40/lens, as it's considdered a precision ground glass optic, and many have special AR coatings.
  #42  
Old 01/11/2008, 11:17 AM
Flybynight Flybynight is offline
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What is the going rate on 20ft legnth of 3/8" titanium pipe ?

And thanks for the link
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  #43  
Old 01/11/2008, 11:29 AM
Flybynight Flybynight is offline
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Haha the guys on www.candlepowerforums.com are as bad as most of us are. Wow we are dorks HAHA jk. Nice link thanks.
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  #44  
Old 01/11/2008, 02:38 PM
big400g big400g is offline
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liveforphysics - which Led’s are you referring to that are better and brighter? I have not yet purchased them and want to have a good light when I am done… as I said I have been planning for a long time and agree that the led choice was 2 years old. Good point on that is that when I first started looking at them they were new and more expensive.
  #45  
Old 01/12/2008, 01:44 AM
Icefire Icefire is offline
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Sorry but Cree XR-E R2 (one of the highest leds output) put out less than the double of a K2. It also cost more.

Unless someone has a PAR meter and an array of leds, I don't believe leds can be used at under 1:1 Watts ratio as MH/T5HO.

GE 48" T5HO Daylight put 5000 lumens per tube, let say 8 tube on a 120. 40 000 Lumens over a 120 so about 34.72 lumens per square inch.

A single Cree XR-E is capable of 240 lumens. To be able to light the same tank with 40 000 lumens, you would need 166.66 leds.

167 Leds @ 4.5W each, you have 750Watts of leds over the tank.
With T5 you would be @ 432Watts.

Current R2 price are 12$us per leds on a star, no lens included. Just in leds it's over 2000$, to light a 120 at near twice the current comsumption of T5HO.

Also T5HO bulb cost 20$each, last near 2 years each. that's only 800$, still WAY less than leds in 10 years.

So what's the point of using leds?
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