Divide cerels into two large baking pans. About 8 cups of corn and rice chex and 4 cups wheat chex in each pan. Place half of the nuts and 1-2 cups pretzels in each pan. Melt 1 stick butter. Add in 4 Tablespoons Worcestershire, 3 teaspoons season salt, 1 1/2 garlic powder and 1 teaspoon onion powder. Repeat for the other pan. Bake pans 1 hour at 210 degrees stirring every 15 minutes.