LED Lighting

[bdejong]

Hello all,

I am new to this board. I took a long hiatus from saltwater tanks (8 years). All I can say is WOW have things changed. I am setting up a small 30 gallon reef and right now it only has the water, substrate and about 30 lbs of live rock. I plan on adding and addition 30-40 lbs more this weekend.

Anyway, right now all I have is the standard 17w plain old top light that came with the tank. While it does light up the tank I know I need something welses before I go farther.

It jsut so happens that I am an engineer for one of the largest led manufacturers in the US, We actually make the led chips. I have been tinkering with using LED lighting on my tank.

Right now I have a light fixture that uses only 20 of our super bright XLamp leds. These are extremely high power white LED's, in fact we recently completely replaced all the metal halide lamps in one of the city s parking garages. Not only does it use 40% less energy it is a lot brighter.

What I am wondering about is what kind of light is required to keep a good reef tank with all the nice inverts and coral? Is there a certain spectrum, color temperature, brightness minimum that I should be looking for? I can imagine that it is not enough to just have a lot of white light. So any information would be helpfull, I am trying to avoid using hot halide lamps and its a good DIY project.

 

[Anonymous]

The LED need to be able to simulate the sun spectrum at sea level (6500K) to about 30 meter (20,000K). Anything in between will be useful. The important parameters that reefkeeper interested in PAR and Kelvin rating.

 

[bdejong]

Good info, we can do that. Our production can be targeted toward certain color points, we bin from cool to warm light. Ranging from 4500K to 8000K. The device has a 100 degree viewing angle.

Here is a link to the datasheet if anyone is interested,

http://www.etgtech.com/pdf/Xlamp/XLamp3_7090.pdf

Here is a picture of the new tank (6 days old now) with the single light using only 20 of the LEDs at minimum rated current. I am going to make another one and see how it looks. I also plan on making one with a few of the royal blues for a moonlight lamp and put them both on an alternating relay setup so that when one turns off the other turns on.

 

[Anonymous]

I will take a look at the PDF file when I have a chance. Sounds promising. Does your company do anything with forward lighting for automotive industry? There are a few LED products out there right now, and some of them can be modified slightly for this hobby.

 

[bdejong]

Nope, we are primarily a die maker. The XLamp line is the only one that we package. Most all of our other line is sold as dice/wafers. Most all cell phones use our die for edge lighting and most of the high end flashlights are using our product as well. There are also interior lighting companies that are now using the XLamps. They are super bright and the wide distribution angle will fit nicely for this kind of lighting project.

 

[bdejong]

Let remember that PAR is not a measurement of light, PAR as I know it is an acronym for Parabolic Aluminum Reflector. They are used for metal halides since they are a round bulb and if you cross section it only 180 degrees of the bulb is directed to the tank, the reflector is used to bounce the other in the direction of the tank. This is where the LED should shine (pardon the pun). The LED is a forward directed device, while most T5 (the little round ones most people are familiar with) have a very narrow beam pattern and as such you would need a ton of them to provide a full spread to the tank. The XLamp device on the other hand has a 100 degree spread and is very efficient.

There is also the benefit of adding either blue or red or orange leds with the white ones to skew the resulting spectrum to mimic the type of light you desire.

Lets think about this as well. Since fish can not close their eyes their sleep pattern is dictated by us. Lets push this one step further, how would we feel if our sun operated on a on or off schedule. Picture being on the 18t tee, its getting toward the end of the day, you place the ball on the tee, get ready and half way through your swing the lights go off. I know my stress level would be through the roof. The sun doesn't work that way, it gradually rises and falls below the horizon. the tank lights should do that as well. Moon lights are not the same, it is still going from 12,000 watts of light to a few watts in a blink of an eye.

What I propose to do is program the lights to slowly transition from full to moon over a period of hours like the real light does. This is very possible using LED's, they can go from full power to minimal with no fall off in color.

What do you think????

 

[bdejong]

Another thought, what would be cooler than a light that would allow you to dial in extra Blue or red, or yellow, or orange. Its your choice depending on the tanks needs. Want the blue hue of an Actinics then turn up the blue, ant the color to stimulate the plant growth then turn up the reds and oranges, throw in a little yellow and you can be all.

This is very possible using a bank of Whites with additional colors with individual control.

 

[Anonymous]

>...Let remember that PAR is not a measurement of light, PAR as I know it is an acronym for Parabolic Aluminum Reflector.

Different speciality has different jargon. In this hobby, PAR is photosynethetic active radiation (IIRC). In non-imaging optic, it means different thing.

 

[bdejong]

Thanks for the correction, wikipedia to the rescue, I understand now. So it is a measure of the area of the spectrum rather that the complete spectrum. I can get that measurement from our spectrometers.


I found out that a company called solaris has beaten me to it. They offer a light like this with adjustable color temp and fading brightness. I carries a 2300.00 price tag for the 48 inch light so its out of the question for me, but it does mean that I have to be careful on how I do it so I don't get into trouble,

Here is an interesting article to keep in mind.
http://www.redherring.com/Article.aspx?a=21087&hed=Could+California+Ban+the+Bulb?

 

[bdejong]

Here is what the first fixture looks like.

 

[Anonymous]

Nice! What is the spec on the LEDs?

 

[mr_X]

make me one in 72"...i'll be a beta tester for you too!

 

[bdejong]

Here is your update. I added 10 Royal Blue LED's to the mix to bring up the color temperature. The measured color temp is approx 17,500K. This is an average since at certain measurement points the spectrometer could not calculate the CCT.

As you can see the blue is peaked now. The color in the tank is great, not over blue but definitely more white.

The extra blues had to be mounted on the sides, so I am expecting that when I make the new housing I will be able to remove a few of them to bring the power consumption down.

All of the LEDs are running at only 350ma each. The light housing is mildly warm to the touch and is mounted about 4 inches above the water. There is no heat transfered to the water. Since reading the review article I am now monitoring the temperature differential from light on to light off. I have yet to notice more than a degree difference.

 

[bdejong]

Nice! What is the spec on the LEDs?

These are XLamp LEDs from the company I work for, Cree. They are high power, high efficiency, cool white LED's. I am currently using 20 of them driven at only 350ma, the low end of their spec. I plan on testing them at higher driver currents, but for now I am starting at the low end.

I just added 10 of the Blue version to raise the Color Temp, which it did on fantastic fashion. I added a switch so that I could turn them on and off. I have asked people to tell me which version they like the best and all of them like the added Blue.

http://www.allelectronics.com/spec/LED-112.pdf

mr_X,

make me one in 72"...i'll be a beta tester for you too!

I would love to, but this thing is a home built setup and I would hate to be responsible for either electrocuting you or burning your house down. . I will say this, its not really that hard to build. The hardest part would be the mounting of the LED's. They have to be Reflow soldered and the substrate is the key to managing the thermal dispersion of the parts. Other than that I am using simple off the shelf constant current drivers.

Here is the LED already mounted on a thermal substrate.
http://www.allelectronics.com/cgi-bin/item/LED-110/340500/1_WATT_WHITE_ULTRA-ULTRA_BRIGHT_LED_.html

Here is the driver that I am using (3 of them)
http://www.mmintrl.com/products/LED_driver/ml350.htm

Now all you need is a housing, you could convert a standard tube housing with some added heat sinking, a little work, and some money.

 

[Anonymous]

Looks promising.

Thanks for sharing. Keep the pictures and updates coming.

Louey

 

[Anonymous]

Excellent work!

I think many of us are waiting for LEDs to come down in price as they seem to offer so many benefits to MH. Solaris may have beaten you to the idea, but their price-point is still too high for most hobbyists.

Are the LEDs in your setup running at normal operating temeperatures, or a bit higher? I've read that heat buildup will quickly shorten their lifespan.

How expensive are they?

 

[SnowManSnow]

the only reason the price is so high is because they have a monopoly on the industry right now. Let a few competitors jump in and the price will plummet.

b

 

[Anonymous]

Actually, Solaris is not charging you a lot for what the components are worth.

We need to get some Chinese factories to crank out the more LED. That's seem to be only way in near future to get the price lower.

Oh, the amount of heat from LED to the tank is pretty minimium. It pretty much only can get rid of the heat by convection and direct contact. Some LED need to have a build-in heat sink so that it won't burn out after a few minutes.

 

[bdejong]

I think many of us are waiting for LEDs to come down in price as they seem to offer so many benefits to MH. Solaris may have beaten you to the idea, but their price-point is still too high for most hobbyists.

Are the LEDs in your setup running at normal operating temeperatures, or a bit higher? I've read that heat buildup will quickly shorten their lifespan.

How expensive are they?

Solaris has gotten there first to be sure and from the reviews I have seen it is a great unit. As far as the price point being to high, that all depends on what you are looking at. Always consider that the LED until will outlast most of our interest or time that we stick to the hobby, they will definitely outlast a MH bulb. With an expected lifetime of 50,000 hours there should be no need for any lighting changes for most of the life time of the normal aquarist. Add to that the energy savings and an argument can be made that LEDs are cheaper - In the long run -

Please correct me if I am wrong since I am new and I have not researched the MH route yet, but I took the following as a basis for starting this project.

The lighting unit I initially looked at had a 250 watt MH bulb, a pair of actinic bulbs and moon lights in one nice housing. the LFS price was around 279.00. Add to that a bulb change every 6 months to maybe a year at say 60.00 for the MH bulb, and 18.00 for the fluorescent tubes.

Let assume a ten year span for the fixture. If we change every year we then have the following additional cost. = 780.00, and from what I have seen the 250w MH bulb can go a lot higher in cost. this assumes no problems with the balast. Add that to 300.00 in inital cost and the rest could be consumed in energy usage. I would argue that they are almost the same.

Not to mention the looks of having to hang them above your tank so you dont overheat the water.

The same sized (24") Solaris unit is 1365.00. I agree this is a lot of money up from but when you consider the additional benifits of no bulb changes, little if no heat exchange means you can mount it close and under a hood, 40% reduction in energy use and you have a winner.

Lets not forget that an advanced design could actually give us the ability to adjust and even choose the color temperature and spectrum distribution. Dont laugh I KNOW it can be done. No more experimenting with different bulbs, just dial your lights in to what you want.

Whew... to long...

Next about the temperature in my set up. The LEDs in my setup are running at only 350ma which is the bottom of the spec ( about 1 watt each). The spec calls out from 350ma to 1 amp. Little heat and the life should be extended. I just need to use more of them to get the brightness I could get if I drove them harder.

The price, they are available for anywhere from 10-14 each on the open market. I am using 30 right now but the additional blue LED are not in the best orientation. I have a new design that will be done this week that should eliminate a few of them and reduce the need for some of the Blue's Even using 20 of them at 10.00 a piece is only 200.00 in LED cost. Again I point to the fact that I will never have to change them. A good MH fixture would set me back at least that much.

the only reason the price is so high is because they have a monopoly on the industry right now. Let a few competitors jump in and the price will plummet.

Not true, while we have the best one, there are several other companies that also have super bright Whites.

We need to get some Chinese factories to crank out the more LED. That's seem to be only way in near future to get the price lower.

Again, not true, most of the Super bright LEDs are already made overseas. They just cost more to make given their special design. They are also harder to produce and since they are binned to specific color temperatures there is more to manufacturing them.


Keep them coming, I love the questions and will try to help all that I can.

 

[Twisted1]

Solaris is not charging you a ton of money for a LED light fixture. If you read the specs on the fixture, it is a LED light fixture with a built in computer that controls the timers on the lights, simulates weather patterns, and from what I understand recently someone claimed they even used the weather pattern control to simulate the lighting cycle required to spawn a particular fish that rarely spawns in captivity. That one is rumor though, the write up I saw for it some where when looking for breeding information claimed he has not been able to reproduce it yet.