Because it contains Quinine, Tonic water naturally fluoresces. So, all I needed was some bottles, some tonic water, a UV light, and a way to shine the light into the bottles in a non-obvious ways. I started with some $7 UV lights that are meant to be used inside of a computer case.
These needed to be run on 12v so I used a small 12v power converter. The lights were meant to be plugged into an IDE HDD power cable and run on 12v. I had to convert from the power supply terminal to the HDD terminal. A little solder and shrink tube and the adapter was made.
We mounted the lights inside a black cardboard box with a hole in the top. This allows the light to shine up into the bottom of the bottles.
We then decorated the bottles and tested out the effect.
Here's how it looks outside at night.
