Combine sugar and water in a small saucepan over high heat, bring to a boil and cook until the sugar melts, transfer to a bowl set over a bowl of ice and stir to cool down.
Place the lime juice, zest and water in a bowl, add the sugar syrup, to taste.
Fill a blender with 2 cups of the limeade, 1/4 to 1/2 cup of tequila (depending on your taste) and 1 cup of crushed ice and blend until combined. Pour into tall glasses. Repeat with the remaining limeade. Garnish with lime wedge.