Pour 2 cups of water into a medium-size, nonreactive saucepan. Using a vegetable peeler, add zest from the grapefruit, orange, lemon, and lime. Halve and juice the citrus fruits; add juice to saucepan. Add lemongrass, citric acid, dandelion root, all spices, and salt to the saucepan. Bring mixture to a boil. Cover, leaving lid slightly askew, and simmer for 30 minutes. Set aside to cool completely.