Step 3: The Light Fountain in action
The second image illustrates that fluorescein fluoresces very brightly under UV light - quite spectacular! You can just see a litle violet glow of the UV LEDs at top and bottom.
The final picture is of the Light Fountain filled with dinoflagellates. Hard to photograph, because they are not nearly as bright - but mesmerizing to watch in person!
We removed the flasks from the setup and filled them with a batch of dinoflagellates (in our example, Pyrocystis Lunula). In a room with minimal light, we reassembled the light fountain, turned it so the flask full of dinoflagellates was on top, and started a stopwatch. The light fountain took about 7 minutes to fully empty into the other flask.
One thing to note is that dinoflagellates need to maintain a circadian rhythm (day and night). They give off light at night in relative darkness. After about a month, they will require a monthly addition of growth media to survive. They were kept at room temperature away from windows or lamps or other sources of heat. This instructable provides instructions on how to care for your dinoflagellates.
Alternative: Other bioluminescent organisms can be used here, such as the Vibrio Fischeri bacteria from this instructable. We have a big 1L culture of Vibrio growing up right now, and will post some more pics when it is ready to glow.