What you see:
- 12" x 1" heatsink (thick base) 1" tall
- 5 3w Cree XP-E LED's. Max 1A.
- 700ma buckpuck with rheostat
- Arctic Alumina thermal epoxy
- 2 male enercell adapta-plug sockets
- 2 female enercell adapta-plug sockets
- various amounts of wire (stranded and thicker than buckpucks 20ish gauge)
- Rocker switch
- 24v 1amp dc power supply (20v should be sufficient but good luck finding it)
- 6.25" x 1" polycarbonate sheet
- Marine Goop
Cost: What you see up in the picture I had to get from two sites. $18 from one and $34 from other. Shipping brought things to $63. The sockets I got from RS (hate them) at $5 a piece. Shopping around online would have probably gotten me quick disconnects for much cheaper. Rocker switch from same place at $4 and I'll be getting a 24v 1amp ac-dc converter for about $18 online. Polycarb was $2 and marine goop is roughly $8. Wires I already had, along with solder, iron, heatshrink.
Total: $115 complete.
You can save a lot by not needing the disconnects (lid will have to remain on top of tank when off) and by already having your own power supply and sealant. That would knock about $46 off.
First you need to cut your heatsink to about 6.25" in length. Hacksaw or if you are lucky, circular saw it.
Next, mix your thermal epoxy and apply thinly but completely around the area you will place the first LED. Leave some room to the nearest edges. Place the positive terminals toward one side (one of the short sides). Place all other LED's in the same direction. To get an even placement, do the ends first, then the middle and then fill the remaining spaces at their mid-points. You may need to mix another little batch of epoxy part-way through. It takes 5 min to start setting up. Once complete, it should look something like the picture below. Allow this to cure for a few hours before handling.
On to some soldering. Cut lengths of wire that will reach roughly the center of each pad from LED to LED. Eye up each length you cut since the LED's will be off a tiny bit one to the next. Once you cut and strip and then tin the 8 pieces you should use a needle nose and hold the ends of the wire down as you solder the ends to the pads. I doubled up my wires to more evenly distribute the heat from the current (not that 700mA is a lot).
Next you are going to drill some holes into your lid. These will be done in the rear so they can't be seen from the front or sides. You need one hole for the power switch and one for the rheostat. Make them as near to the top as possible.
You can now start soldering the buckpuck to the power switch and attach your quick disconnects (one on LED side and one on input side). I wired my power switch across V+ input. The picture below shows my rough final placement. Once all is good, marine goop will be used to cover the buckpuck and rears of switches and to bond certain wires to the lid. The sockets seal pretty tight but if the idea of having them under the lid is bothering you, you can extend the side connecting to the buckpuck a bit and ensure that they both end up in the rear compartment with the stock lighting connector.
Here is what the rear of my lid looks like. It's upside down obviously, so when on the tank, the rocker switch will be in the top right rear side. In retrospect, I really should have looked for a smaller one and placed it even higher. As it is, my switch is dangerously close to pushing on the filter a bit. Wont bother anything though.
Finally we are ready to test things prior to gooping everything and attaching the plastic cover over the LED's. Wire your other socket to the DC adapter and the last one to two wires you solder to the final positive and negative pads on the lightbar. Ensure your positives and negatives are all where they should be and that your rocker is switched to off. Also ensure that the rheostat is roughly mid-level. Connect the sockets and plug the DC power supply in. If you did things right, nothing should be smoking or sparking or lit up. Now flip your rocker switch and you should see some fairly bright light. Turn the rheostat to full. This is what you should see as you become blind.
Play with the rheostat slowly. The LED's will turn off well before the full counter-clockwise motion is reached.
Turn the switch off and disconnect the power supply. Disconnect your sockets to the light bar and power supply. Glue the lid up and allow to sit for a day. You can rough up the lid parts that will contact the goop with sandpaper if you want.
Gluing the cover over the LED's is fun. We are going to cut out the 1" x 6.25" polycarbonate and then cut out slivers of roughly .25" to create the sides to our lid. Notches can be cut out on either short side for the positive and negative leads. Goop will then be used to bound the sides to the lid and then the lid to the heatsink. Once complete, allow the goop to cure for over a day. It should not really smell when fully cured.
I will be completing this part later today.
Once the lightbar is fully cured, you can attach it to the stock light housing a couple different ways. First, you can goop it to the light. Also JB weld will work. This is not really unsafe, but if it's not enough for you, you can screw in tiny metal L brackets onto the stock lighting that will travel down and under the LED cover on your lightbar and then goop it in place. It should _JUST_ fit.
Hopefully tomorrow I will have some pics of before and after in the tank. You should end up with well more than enough photosynthetic friendly light for any reef need. The light bar adds well over 5x the amount of light than in the stock LED unit and all of it is useful photosynthetic light as opposed to much of the wasted white LED light in the stock unit.