Sea Creatures in a tub of Tonic Water with Quinine
This kept the 2-year-old (and myself) so happy for a very long time.
It was quite chilled.
All we needed was a whale song soundtrack.
It looked pretty effective when you made waterfalls with your hands.
Bathtime with the Vitamin B Water
Super fun, but I think that the bath would need to be a more concentrated solution to really glow. Just tipping in a few jug fulls didn't do much, but the little guy was happy anyway!