Preheat oven to 400. Combine the sauce and water in a mixing bowl. Stir in the ricotta, parmesan, and 1/2 the mozzarella, then the uncooked ziti. Spoon the mixture into a 9x13 baking dish and cover with foil. Bake for 55 minutes. Remove the foil, sprinkle with the remaining mozzarella, and bake for an additional 5 minutes.