How to Make Black Light Lemonade by Celeste Smith. Don't you think something is more exciting if it glows in the dark? Take plain old lemonade for instance…The secret here is Tonic water. It glows under black lights (remember the glow in the dark cupcakes?) Step 1. Pour tonic water into a punch bowl or glass carafe Step 2. Add powder lemonade mix to taste *no ice as it will dilute the tonic water Step 3. Place under black light and watch it GLOW! …This ain’t yer grandma’s lemonade!