I'm guessing all of you know more about electricity and wiring than I do, at least up until a few days ago. I've been surfing and reading about LED lights for the past week because I want to include some soft lighting for my next indoor fountain. Apparently, LED technology has really advanced in the last few years (I wouldn't know that if I hadn't read it). Anyway, you can get some really bright LEDs in almost any color, and their estimated lifespan (if installed correctly) is 100,000 hours. That's over 11 years, so it shouldn't matter if the wiring is permanently embedded in the tufa. I got 50 super bright LEDs from Ebay for less than $10. Add resistors, and a 12V power supply and the total cost should be less than $20.