Stir together grits and water in a 3-qt. slow cooker. Let stand 2 minutes, allowing grits to settle to bottom; tilt slow cooker slightly, and skim off solids using a fine wire-mesh strainer. Cover and cook on HIGH 2 1/2 to 3 hours or until grits are creamy and tender, stirring every 45 minutes. Season with salt and freshly ground pepper to taste.