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     Project:  A DIY Light Rack for Metal Halides and T5s

One of the first things I tackled for the Glass Reef was the light rack. For months, I had a plan going through my head about exactly how I'd put the lighting together. I knew I wanted an open aluminum frame: lightweight, rustproof, easy to work with, fairly inexpensive. It had to be mobile. I want to be able to move the whole thing away from the tank, in order to get better access. I wanted Metal Halide, supplemented by T5, so I searched the internet to see what kind of ideas were out there.

Lighting components

I spent a good many hours researching metal halides. At the time, the most popular bulbs seemed to be the Radium 20Ks. Problem is, I'm not really so fond of excessive blue light over a reef tank. In the end, I finally decided on four 400W dimmable ballasts from CoralVue with 12K ReefLux SE bulbs.

Deciding on a reflector, for the halides, was a little more difficult. I originally wanted to go with the large LumenArc IIIs, but then I started hearing good things about the new 20" Lumen Brights from CoralVue. I was a little worried about the fact the Lumen Brights throw a fairly concentrated narrow beam and my tank is 36" - front to back. In the end, I decided to give the Lumen Brights a try.

As for the T5s, I only wanted them in order to extend the lighting period. They would be on for two hours before and four hours after the metal halides. They were not intended for spectrum augmentation, so I went with four 36", dual bulb, retro-fit kits from

The light frame

At first I was just going to get some 1" aluminum tubing from Lowes, for the light frame, and do a lot of cutting and riveting. Then I happened across an aluminum construction system from It consists of 1" square tubing (with or w/o flanges - you'll see the flanges, later, in the pics). The tubing can be fitted together with fiberglass reinforced composite connectors. I had experience with this kind of system while I lived in Europe, so I knew that they produced very strong structures. Seemed like the perfect thing for a light frame so I placed an order. Cost was comparable to what I would have paid at Lowes for regular tubing.

Since I first mentioned EZTube in my original build thread on Reef Central, I've been told dozens of reefers have used the material to build their light racks and canopies. Glad I could play a part in introducing a new DIY method into the hobby.

Here's what I received:

Here, you can see what I meant by flanges:

The flanges are actually intended as a base for flat (ply or MDO) panels when the tubing is used to create cabinets, etc. The panels then become the top, sides, bottom, etc. of the cabinet. The pic shows a tube with flanges on both sides. Tubes are also available with no flanges or only a flange on one side. The composite material connectors are driven into the ends of the tubing. You have to use a hammer, and a little muscle, to do this as the fit is very tight. Once it's seated it produces a very strong connection. Make sure you have measured your tubing lengths accurately - after the connectors are in the tube you can't get them back out:

I cut the tube with a power miter saw and carbide tipped blade - cut like butter:

Because I was going to have a lot of right angles, I often had to miter the flange portion of the tubing at 45deg:

I found some aluminum rails (made by Stanley) at McMaster-Carr. They're used for sliding closet doors, etc. They come complete with rollers and hardware, and are rated for 250lbs. And, they were cheap.

A look at the components

So, having found everything I needed for the light frame and suspension, I ordered the lights. Here's a pic of all the parts that comprise the light (except for the two electrical outlet boxes and the moonlights). A heckuva lot of parts!

The HO T5 ballasts are made by Advance. I don't think they're the best out there, but the T5 lights are only intended as supplemental lighting, so they'll do.

The T5 hardware kits from are very complete. Everything required is included:

As far as the T5 bulbs are concerned, I ordered four 10000K and four Actinic. As for the metal halide equipment, all the CoralVue stuff looked to be high quality, of course, only time will tell.

The Lumen Bright reflectors seem to be good quality equipment. Sturdily built and they have a perfect mirror finish.

Putting it all together

I began the light frame by cutting all the tubing to the correct lengths. I cut miters, where necessary, and cleaned up all the edges. Bye the way, this is a situation where you'll definitely want to follow the old adage: measure twice cut once - mistakes here can be hard, or impossible, to correct. After banging all the connectors into the tubing, I ended up with a flat rectangular platform with four squares of equal size. The overall dimensions of the frame are approx. 90" X 30".

Should decide to use the EzTube components to build your light rack, make sure you think about the order in which you will assemble the pieces. Depending on the complexity of your frame, it's easy to get into a position where you are not able to attach a particular piece to another, because a piece is blocking your work.

The squares are dimensioned so the reflectors will just fit inside the tube and set on the flange, but not so large that the reflectors could fall through. This has the advantage of not requiring the reflectors to be fastened, in any way, to the frame. They can be easily removed, from the frame, at any time, for cleaning, repairs, etc.

There is an extra tube along both long sides of the frame. They produce four narrow rectangles that will be used to hold all the T5 hardware:

After I got the frame itself built, I started working on the hanger supports which will attach the frame to the stainless-steel chain that hangs down from the slide rails on the ceiling. I originally had planned on making the support plates out of aluminum, but was a little shocked at the price. I decided to use some black 3/8" acrylic sheet I had laying around. My first thought was "bad idea" because of the heat involved, but after considering it a while, I decided it shouldn't be a problem. Also, I liked the idea of using the acrylic because it would effectively isolate any non-aluminum metallic hardware from the frame, itself. Steel touching aluminum in a wet and salty environment can cause corrosion problems.

Here is a hanger support plate. I used aluminum rivets to attach the plates to the frame. Worked great! Easy, fast, and clean:

The center hole in the plate is where a stainless-steel eyebolt will be attached to the chain from the ceiling. Here's the plate, shown from the bottom, with the eyebolt (eye is on the top-side) attached.

And from above:

I went ahead and used acrylic sheet as a base for attaching all the non-aluminum harware to the frame. For example, here a T5 end-cap assembly has been attached to an acrylic base. I used nylon bolts and cap-nuts here. Truthfully, I probably went a little overboard in worrying about corrosion, but, we'll see:

and then riveted to the frame:

I tried to make the wiring as neat as possible. I've learned in the past that sloppy wiring leads to accidents and frequent repairs:

The T5 ballasts were also mounted to the frame using rivets. Worked real well and allowed the ballasts to be mounted in a way that left them exposed to air on all sides, which should help in keeping them reasonably cool:

Here's the completed ballast connection:

And because it looks so nice, I'll show it a little closer:

Here are a few pics of some of the construction details:

I decided to attach all the electrical components of the light frame to the power panel using cables with normal power plugs at both ends of the cable. I didn't want anything hardwired so that changes and repairs would be as easy as possible. Having plugs everywhere would allow quick removal of most components.

I attached two PVC outlet boxes to the frame - basically, one for components on the right side of the frame and one for components on the left. First, I attached four 1" Sq. aluminum tubes to the frame - two for each outlet box. I had to drill 5/8" holes in the tubes, wherever a rivet was needed. This allowed the riveting tool to be used inside the tubes:

Here's a completed outlet box. I like to label all electrical connections so there won't be any accidents later when I can no longer remember what I put where:

I hooked up each MH reflector separately and the T5s all on one outlet. The other box has the two MHs on the right side, the fans on the right and the moon-lights.

Here you can see how I "double-plugged" the MH reflectors to allow easy removal (you can probably tell from my somewhat obsessive attitude about easy component removal that I've had my share of problems in the past:

Well, the result of all the cutting and riveting and wiring and swearing. For all you electricians out there that might want to comment on the fact that wires are entering the junction boxes without being correctly attached - all wires entering the boxes are strapped down, inside the boxes, using a metal wire strap. There is no danger that they might be pulled out:

My wife says it looks like the inside of Scotty's control room on the Enterprise:

Assembling the rack's power panel

So it was time to build the power panel for the light rack. The lights and fans will be on their own 30A circuit (if the electricians ever get the sub-panel problems sorted out). I built a 15" X 36" backer board out of ply covered with FRP and attached it to the wall above and a little to the right of where the light frame will hang. Then I mounted the four dimmable 400W ballasts:

The whole system will be controlled by an AquaController III Pro from Neptune Systems (NOTE: the AC-III Pro was upgraded to the new Apex Controller - also from Neptune - great controller, BTW). As part of that control, I mounted a DC4-HD (has 4 heavy duty controllable outlets) for the Halides, and a DC8 (has 8 normal duty controllable outlets) for the T5s, fans, etc.

All together, it looks like this:

The little blue box on the right of the pic is the Neptune Lunar Simulation Module. It plugs into the DC8's data port and controls the moon-lights so that their brightness and on/off times are according to the actual lunar cycle. Notice that a power line (above the panel) now connects the panel to its circuit.

I built a power "umbilical cord" to connect the light frame to the power panel. I had to make sure that there was enough slack in the UC to cater for the frame being moved out (up to 40") from the tank. Here it is half done:

And completed and attached:

Adding the moonlights

I then added the 5 moon-lights that came with the Neptune Lunar Simulation package:

Just about done

Well, other than the cooling fans - they'll come later - the frame was done. All that was left was to turn it on to see if everything worked. So I did - I thought of a biblical quote here, but ...

Gosh - it works. I'm making jokes, but you can't imagine how relieved I was. It doesn't look very bright here, because of the exposure I set on the camera, but MY GOODNESS!!! - talk about a vitamin D shock ... And here are the moon-lights:

And that completes the construction of the light rack.

UPDATE (10/24/2010): Well, the light rack has been in use for 22 months, now. All of it's parts look as new as the day they arrived at my door. No rust, no warping, of any kind. The choice of 3/8" acrylic for the various parts of the rack has proven to be a good one. An interesting experience with the rack is the fact that you can touch any part of the frame and components (other than the lights themselves, of course) with your bare hands and the worst heat you'll experience is just warm - nothing that could be considered hot. Not to say that the 400W halides don't produce high temperatures - they definitely do, but the great preponderance of that heat is directed downward toward the tank, where the cooling fans help to dissipate it. Likewise rust has turned out not to be a problem. The use of aluminum tubing, aluminum rivets, acrylic, good quality stainless steel, and nylon screws/bolts, has proven successful.



1 2 > [last]
LorrieCox says...
Hello, my friend!
Where to buy XRumer 12.0.20???
It is the best software for SMM.
Thanks you.
27th November 2016 8:40am
Mohamed says...
Amazing work . I'm following your lead currently to build the same for my 270 gallons drop off tank. I have one question. I can't see any T5 reflectors. Have you depends on the metal halide Reflector for T5? And if this is the case can you please share how you figure out the right angle.
GlassReef: Yes, there are "snap on" reflectors on the T5 bulbs. I just set the angle for the rear T5s to approx. 35 degrees forward. The front reflectors are set to 35 degrees to the back. Hope that helps.
26th June 2016 4:31pm
Carlos says...
Hi. Im in the process of ordering rails from eztube and wanted to ask which flange tubes you used.

They offer:
-3/4" Recessed Panel
-1/4" Flush Panel
-1/4" Recessed Panel

Thanks for your help.

GlassReef: I used 3/4" recessed.
4th November 2014 8:28pm
LAM LY says...
very impressive and clear detail, Thank you for sharing.
from your experience, how long does the reflex 12K last?


GlassReef: I usually get 6 to 7 months out of them.
19th October 2014 12:05pm
Dave Anderson says...
Man this is AMAZING! Love this light rack...I will follow your lead on this! Well done Sir!
14th June 2013 12:31pm

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