01 -  Combine tart cherry juice and magnesium powder in a glass. Stir thoroughly until magnesium is fully dissolved. 
 02 -  Incorporate ice cubes if preferred. 
 03 -  Top with chilled seltzer water and gently stir to blend. 
 04 -  Garnish with a lemon or lime wedge, if desired. 
 05 -  Serve immediately as a calming pre-bedtime beverage.