Wednesday, September 19, 2012

Robert's DIY LED Light Fixture, Part 1

DIY LED light fixture from a MarineDepot.com staffer
With all the recent excitement around LED lighting, I could not resist the temptation to make a change. I was previously running a 250 watt metal halide over my 24” cube reef aquarium. We've experienced some killer heat waves in California and the tank was running consistently above 80 degrees and definitely suffering. I was a bit hesitant to drop the ball and buy a Radion, but definitely wanted to see what LED was all about.


Ecoxotic Panorama Pro Module
Thanks to the great people at Ecoxotic, I had a couple of the Ecoxotic Panorama Pro LED Modules in the blue/magenta color. Along with two of the Current USA TrueLumen Pro LED Striplights in the 12K white, I figured this would be a pretty nice spectrum. Now I was fairly certain this would not equal the PAR values of my 250 watt MH, but I know it is best to slowly acclimate corals when switching to LED. Therefore, I figured I could always add more strips in the event I need more light.

I started by taking a part an old 24" Coralife Lunar Aqualight T5 Lamp High Output Fixture that was used on a previous tank. It was pretty simple to remove all of the existing T5 ballasts and sockets. I simply had to unscrew the end caps and remove the acrylic splash lens. All of the internal parts are mounted with Phillips screws on tracks and I only had to cut the power wires leading to the ballasts. Everything else came out by loosening the screws.

I noticed the fan and LED moonlights were powered by a separate DC power adaptor on a separate circuit. I carefully left these wires in place as I figured it would be great to still have the fan and moonlights operational. This proved to be a smart move as it worked out great in the end and is helping to keep the LED strips cool.

Next, I had to find a way to fit the strips into the housing. I found it would be best to mount three strips inside the fixture and one on the outside. The Ecoxotic strips are fairly resistant to moisture so I attached this one to the outside in between the moonlights.

The 24” Current USA True Lumen Pro Strips did not quite fit inside. I used a Dremmel tool to carefully cut out one of the plastic end panels and the strips fit perfect.

I proceeded to utilize the two mounting brackets that came with the Current USA strips to attach them to the existing tracks in the fixture on one end. The other end was held in place by the plastic end panel.

Then I used some black RTV silicone left over from an intake manifold job on my car to attach the Ecoxotic strips. I knew it would hold strong and be resistant to heat. My only concern was how it would affect the heat sink on the LED. I knew using too much silicone would hinder the heat from dissipating away from the LED strips. Therefore, I put a hefty amount on the end brackets and left the heat sink to rest directly against the aluminum fixture. A couple hours later, the strips were in place and seem to hold pretty nicely.

I fed the LED power supply and splitter wires through the existing power cable holes in the Coralife fixture. I set up the mounting legs and mounted over my tank that same night. For only about 4 hours of work and a bit of ingenuity, the tank is running cooler and I can’t wait for next month’s electricity bill!

The shot below was only 3 days after the switch and still is running great to this day. I have plans to add one more strip in hopes to get a bit more color out of the corals. As of now, I could not be happier with the tank. Check back for updates!

Robert's 24-gallon nano reef illuminated by DIY LED light fixture