In a large, heavy saucepan stir together sugar, corn syrup, and water. Cook over medium heat, stirring constantly until it starts to boil. Now cook without stirring until it reaches 280 F (about 10 minutes). Now stir in peanuts & continue cooking while stirring constantly until it reaches 300 F degrees. If you don't stir, the peanut will burn as they sink to the bottom. Remove from heat and add baking soda; mix well. Pour candy mixture onto 2 large cookie sheets lined with parchment paper – no spreading necessary. When the candy cools, break it apart into small pieces and store in airtight container.