Seachem NutriDiet Fish Vacation Tablets are a complete food for all types of ornamental fish, and they come in convenient tablet form for use during absences. Seachem NutriDiet Fish Vacation Tablets contain food throughout the tablet, allowing your fish to eat from the moment they are placed in the aquarium. There is no need to wait for the surrounding material to dissolve to reveal the food. Directions Add one tablet for every four inches (10 cm) of fish length for livebearers, tetras, or barbs, or one tablet for every three inches (7 cm) of more voracious or larger fish such as small cichlids, goldfish, and rainbowfish. A water change is recommended upon return.