This tropical flavored celery smoothie is yummy and fresh, and filled with good for you ingredients!I like to use frozen fruit for 2 reasons. First, it thickens up the smoothie. And second, it makes it cold without having to add ice, which I always find makes for a watered down smoothie. Special Tip: You can add a scoop of vanilla protein powder or unflavored collagen powder to boost the protein and make this a meal replacement smoothie.