An Excellent Daily Diet Or Treat for All Types Of Freshwater and Marine Fishes, Invertebrates and Other Marine Species. Great For Turtles and Frogs Too. Bio-Pure FD is the world's cleanest freeze-dried fish food available today. Pharmaceutical freeze-drying techniques allow us to give you a product as close to fresh as humanly possible. Expect a texture and taste not previously available in a freeze-dried food.