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 else before I go farther.

It just 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 help full, I am trying to avoid using hot halide lamps and its a good DIY project.

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

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.

[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.

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.

What do you think????

[reeffreak]

They do sell LED's for aquarium.Solaris LED Hood PFO lighting Inc > Home ( DNN 4.0.3 )

I read up on this type of lighting all over the web and aquarium magazines.It would seem that the jury is still out on them.

12,000 watts to a few watts?You was kidding right.I never heard of anybody running 12,000 watts.Actually dust to dawn is the transition from lunar to actinic(sunrise) to daylight then back to actinic then lunar lights.Its not as drastic as you make it out to be.

I am curious about how this turns out for you though.
Keep us posted.

Personally to keep any coral or clams Mh's are the way to go.
Some say if your tank is shallow enough,oh 20inches or less than VHO's or T-5's with individual reflectors should work.

[yote]

I have thought about trying to set my lights up to gradually brighten and dim to simulate dawn to dusk.Even thought about trying to get one of those solaris fixtures.But at 2300 bucks that would have been a sure divorce.
I do how think that even using actinics to simulate dusk and dawn is not natural,I dont think it causes and stress to our fish or corals,but its not natural.Spend a morning or evening and watch how the sun rises or sets and youll notice that if very gradual.
Just my 2 cents worth

[bdejong]

They beat me to it. I had not heard about the solaris, but yes that was the idea. $2300 would indeed be a divorce purchase, even the 800 small unit would cause several nights on the couch.

12,000 watts, I read someones post that quotes 12,000 watts. Could be overstating, could be real. I was only trying to get the point across that he sudden transition could be a point of stress, maybe not enough to cause harm but hey anything we can to to make our pets happier right

What is it about MH's that make them the best? I have been trying to find that information but I can seem to. I think they are popular for our hobby for the same reason they are popular for street lights and large area lighting, they put out a lot of light for their small compact size, and once started they are efficient. They are available in several color temperatures, for those that don't know that is the 8000k to 12,000k number.

If the same amount of light (brightness) can be achieved at the same color temperature then I don't know why LED's couldn't be a direct replacement. I can tell you that it is absolutely possible with LED's to get the same color temperature and brightness of a MH bulb with high power LED's. I can also tell you that it is possible to do this using less power.

Here are some other interesting article that you may wish to read.

http://www.redherring.com/Article.aspx?a=21087&hed=Could+California+Ban+the+ Bulb%3f

Photos: LEDs light the way in Raleigh | CNET News.com


The idea of variable color temperature is as simple as adding colored LED's to the mix of whites. Even the whites can come in several different color temperatures.

Add the cost saving and reduction in heat generated it is only a matter of time before these are mainstream.

I will keep you all posted on how it is working. This is a definite project for me and I already plan on measuring several MH bulbs in the lab next week to get a good baseline for their replacements. Since we have already done a lot of this work before for other projects I have a good idea as to what it will take to get the job done right.

Thanks
Brian

[yote]

I think that that th MHs put out more lumens or something like that.

[bobby]

Sounds cool, cant wait to see your diy setup. Good luck.

[bdejong]

I think that that th MHs put out more lumens or something like that.

Yup, they put out a ton more light for their size compared to standard compact fluorescent tubes. From what I can gather that is the main reason they have become popular. Compact size, lots of light, and basic housing. To me the only downsize is cost and heat. Please do not take that comment as a digg against the MH lamps, it is not. In everything we do there are pros and cons. The above are some of the Pros and a con, the LED solution will have its pros and cons as well. The biggest con will be the initial cost,but that will hopefully be earned back by the pros of less heat and less energy usage. As noted in the Parking garage installation they have found a 35-40% decrease in energy usage and they predict it taking only a few years to recover the cost of the install, after that its all savings. The lifetime rating of the LED is 50,000 hours, thats 13.5 years running at 10 hours a day. A definite Pro.


Here is what the first fixture looks like, very simple construction.

[bdejong]

Here is a pic of the current light.

[reeffreak]

MHs are considered the best I think is its ability to penetrate the deepest parts of the reeftank.I definitely not an expect on MHs so hopefully a moderator here may jump in with their experiences.

What I read on another forums,some moderators test these LEDs and their coral didn't open well under them.I know some coral may open alot when they are not given enough light,so I'm not certain that this was the case.Their final statements were that they felt that LEDs didn't penetrate the lowest part of their reeftanks like medal hallides and that it would take more LED bulbs then a standard size fixture to accomplish comparable results to medal halides.

I curious to know how you incorporate the slow transition from dusk to dawn.In my mine,that would seem like a gazillion timers.Is their an alternative to the bulky outlet kind and the digital ones that can transition the amount of LEDs needed for a more realistic day cycle?