Step One: Gather materials.
Nontoxic yellow highlighters.
A blacklight fixture or flashlight.
Step Two: Pop the back off of the marker and pull out the ink soaked felt that is inside.
Step Three: Then run the ink-soaked felt under a small stream of water with a container underneath to catch it.
Step Four: Squeeze the felt as the water runs over it to get all of the neon coloring out of the highlighter.
Step Five: Observe and discuss the glowing water.