I posted this in my build thread (link in signature) but thought it would be helpful to anyone looking to add LEDs to their Spectra.
I installed of a pair of Kessil A160 WE Tuna Blues into my Geissman Spectra. This was no easy task. It took the majority of a day to complete. I started the night before as I needed to minimize the amount of time the light was not on above the tank. That night I disassembled the Kessil lights. To do this I needed a very small hex key,or allen wrench. Home Depot didn't have one this small but I found one in a Kobalt micro electronics kit at Lowes. This kit also had some other tools which were helpful. Once I got the external can off I needed to separate the light and fan portion from the controller portion. These were held together by long screws. The electronics and wiring inside the Kessil are coated with clear rubber which is a great idea. This obviously helps with any moisture and it made working with the internals of the fixture much easier.
I did not remove the fan because of I would have had to disconnect the cable which was rubber coated. It would have been simple to do, but the fan didn't get in the way and I thought as long as it provides some cooling and doesn't cause problems I'll leave it. Now that it is all in place, there is a slight vibration from the fan to the glass and screen plates. As long as those plates are tight there's no noise. Depending on how they're positioned there can be noise. Easy to fix whether securing the plates, or going back in to remove the fans. I have the plates tight, so no noise.
With Kessils disassembled the night before, I was ready to pull down the Spectra. The next morning I did this and began figuring out how to run the cabling. I had an idea based on another person's experience with an Infiniti fixture posted in this thread. I had cut the Kessil power cords and attached them both to a terminal block, also from Lowes, the night before so I was ready to power both lights through a single power cord. This is the end power cord, not the power supply portion. I tried to run the power cabling through the T5 portion of the fixture, but the hole between MH and T5 was too small. I could have bored it but didn't want to mess with that, so I just ran the thin cabling of the power supplies behind the MH reflectors. I used cable clips to keep them from touching the reflectors or anything that could get very hot. I found these cables to be long enough so that I could run them all the way out the Spectra fixture itself and the power supplies themselves could be outside of the fixture. This helped a lot with the space constraints inside the Spectra and eliminated any heat concerns. I was also able to use new independent power cables instead of the ones I cut and connected to the terminal block.
The biggest problem was gluing the Kessil lights into the screens. With the 72" fixture there are two blank spaces between the halides in the middle, and two at the end. I wanted the Kessils in the middle spaces for good light distribution. I tried to remove the halide reflectors so I could glue the Kessils to the screens outside of the fixture first. This was not easily done, they are very tightly pressure secured. I also tried sliding out the screen on the top to glue the Kessils in that way, but it was also pressure secured. The only way I saw to do this was to glue the Kessils in with the screens in place, but slid over. I cut the holes in the center of the screens outside of the fixture with a Milwaukee hole cutter. I think it was about an 1" or a little more in diameter. Larger than the glass lens for the LEDs so the Kessil reflector sat properly against the body, and no glue got on anything. I then inserted the screen back in, positioned the Kessil within the Spectra and applied 2 part, fast drying, Gorilla epoxy to the Kessil body. With the Spectra lights facing down, I then positioned the Kessil under the screen and had to hold it there for at least 5 minutes before the epoxy was cured enough to keep it without my pressure. Because the lights were facing down I had some flexibility, and it wasn't as hard to hold the Kessil in place. I secured the first Kessil with the lights facing up and it was much harder. Once the Kessil body was secured I epoxy'd the Kessil reflector to the outside of the screen.
Something I learned along the way was that the middle glass over the halide will be difficult to remove when time comes to change the bulb. I had the glass out when I glued in the Kessils. In order to put the glass back in I had to stretch the body of the Spectra a small amount so the glass would drop into place. I will need to do the same to change the middle bulb. This shouldn't be an issue, but will require two people and be a PITA. There was no way around this considering I wanted the Kessils in the middle blank spaces of the fixture.
