Preheat the oven to 250 degrees F. Mix sugar and cinnamon together in a small bowl. Whisk egg white and water together in a large bowl until frothy. Toss pecans in the egg white mixture to coat. Slowly pour in sugar mixture and stir until pecans are evenly coated. Spread onto a baking sheet. Bake in the preheated oven for 10 minutes. Stir pecans and rearrange into a single layer. Continue to cook, stirring every 10 to 15 minutes, until pecans are evenly browned, another 30 to 50 minutes.