In a large pitcher or bowl add grapefruit, ginger simple syrup and limes juice. Muddle, add tequila and ice. Fill container with lemon-lime soda.
Garnish with lime wedges
Add water, ginger and the sugar to a saucepan and bring to boil. Stir until sugar is dissolve. Strain. Let cool and store in the refrigerator in an air tight container.