Tetra Vacation Tropical Feeding Block is a slow-release feeding block full of quality nutrition designed to feed your tropical fish for up to 14 days. The 100% plaster-free gel-based block will not dissolve and when used as directed allowing you to leave it in the aquarium even after regular feeding is resumed. It is designed to be used when you re away from your tank for up to 2 weeks allowing fish to eat from the block as they become hungry. This block won t disintegrate on its own food is released when fish nibble on the food.