1 x Yellow Highlighterm, others work but this gives the best light.
1 x Container, a plastic test tube in this case
Some water and a Black Light
get your container a small plastic test tube from a magnetic experiment set in this case. Remove the top and make sure it clean of what ever was in it prior. Fill it with some water about three quarters works.
Take you highlighter and pop the case to get at the ink. Note how bright the cover of the highligh alone is.
Remove the cover off the ink filter and squeeze a few drops in to the water. I used 5 in total to make sure it lit up good. Put the cover back on and switch on your Black light, result.
Main light on UV off, Main light & on UV on, Main light off UV on
stick on left is a highlighter ink stick that fell in.