Tangy Slow Cooker Pork Roast

1 large onion, sliced
2 1/2 pounds boneless pork loin roast
1 cup hot water
1/4 cup white sugar
3 tablespoons red wine vinegar
2 tablespoons soy sauce
1 tablespoon ketchup
1/2 teaspoon black pepper
1/2 teaspoon salt
1/4 teaspoon garlic powder
1 dash hot pepper sauce

Arrange onion slices evenly over the bottom of the show cooker, and then place the roast on top of the onions. In a bowl, mix together water, sugarr, soy sauce, ketchup, black pepper, salt, garlic powder, and hot sauce, pour over roast. Cover and cook on low for 6 to 8 hours or on high for 3 to 4 hours.