Zoo Med Nano Banquet Food Blocks are specially formulated for feeding nano aquarium species of crab, crayfish, fish, and shrimp. Each block is packed with Plankton and Spirulina to promote the long term health of your aquarium inhabitants. Ideal for use as a vacation feeder or as a supplemental food source for picky eaters. Nano Banquet Food Blocks will not cloud your aquarium water. Great for both freshwater and marine species. Proudly made in the U.S.A.