To prepare the citrus, wash and slice off each end. Using a very sharp knife (serrated knives work great), slice each fruit into 1/5" slices, removing any large seeds, and set aside.
In a large, wide pan, add the water and 2 cups of sugar and bring to a boil over high heat. Add slices of citrus to the pan in a single layer, placing just enough in at a time so that the edges touch but don't overlap.
Reduce heat slightly and cook at a low simmer for about 30 minutes, turning the slices over half way.
Meanwhile, spray a wire rack with nonstick cooking spray and set it inside a baking sheet. Once the citrus are tender, use a slotted spoon or a fork to remove the slices from the hot simple syrup and place in a single layer on the prepared cooling rack to drain for about 15 minutes. Continue cooking any remaining citrus slices.
Once they have all cooked, place the remaining 1 cup of sugar in a side bowl and dredge each candied fruit slice to cover completely, then return to the wire rack to dry completely for 12-24 hours at room temperature, flipping them over once.
Once completely dried, use to decorate cakes, cookies or even eat plain. Store in an airtight container in a cool, dark place at room temperature for up to 1 month. Enjoy!