[mike31154]

Although my lighting set up would be considered in the ghetto category, I do have at least one suggestion that you could look into. LED tubes to replace standard fluorescent tubes are slowly beginning to appear on the market, so that might be a possibility for your 18 inch T5 fixture. All you'd need to do is change out the current fluorescent tubes with LED replacement tubes, no need to gut the fixture. I had a couple of links ready, but if you search the net for LED/T5 fluorescent replacements, you'll have plenty of sites to browse. The only problem is finding the right colour temperature for marine aquarium use. In your case, for supplemental use only, might not be too difficult to source something appropriate. Not sure there are many 'dimmable' options in this tube replacement form factor yet though and be ready for a bit of a price shock for anything decent.

I've certainly been keeping my eye on the development of LED lighting technology for aquarium use, but find the progress slow and much too costly at the moment. Seems like the best solutions so far for high powered LED lighting is the DIY scene. There seems to be no happey medium, either super elaborate and way over priced or too cheap and low powered to consider for our use. Even the LED products available for home use seem to be progressing inordinately slow. I'm getting more and more frustrated at the continued marketing focus on CFL bulbs with the mercury and gas content making them a pain to dispose of in an ecologically safe manner.

Anyhow, take a look at the tube replacement option for now, other than that, play the waiting game like me. I really should DIY myself a nice LED fixture since I have the electrical background, but still find even the individual components like the CREE LEDs quite costly if you're looking to build something for a 4 foot or larger tank.