For the simple syrup, microwave water in a microwave-safe 4-cup glass measuring cup at HIGH 1 minute and 30 seconds or until very hot. Add sugar and stir until well combined. Microwave on HIGH for 2 additional minutes. Stir until sugar is dissolved and mixture becomes a clear syrup. Set aside to cool.
Add strawberries and 1 cup cold water to a blender container. Pulse until the mixture is fairly smooth.
Add lemon zest, lemon juice and 1 cup cold water to a half-gallon pitcher. Stir in the strawberry puree and simple syrup until well combined.
Add lemon and strawberry slices and ice.
Taste and add more cold water if needed. Serve over ice.