Wardog: Cool link, thanks. I learned a few things
It'll be interesting to see their findings after their little experiment.
Wildechild: Much depends on your goals. If you're looking to DIY the fixture and controller to save money... save it elsewhere.
If you just love to tinker and build stuff, wow your friends with your creative process... then DIY LED's are for you. I started my build with the thought of saving, but I bet in the end I'll have saved nada, lol
But in all fairness, I've had a blast doing it and I think it's cool. That's all that matters on "my tank". I bought all the components - ledgroubuy, eBay, and other locations. I built a Jarduino controller, from scratch, but now you can buy remade controllers like the one Blue World Aquariums in Victoria makes.
Lots of knowledge here to help you build one if you want to. But don't rush the process. Understand what you're doing. It'll be much easier to diagnose and fix anything in the future.