Tetra® Weekend Tropical Feeding Block is a slow-release feeding block full of quality nutrition designed to feed your tropical fish for up to 5 days. The 100% plaster-free, -based block will not dissolve and when used as directed, allowing you to leave it in aquarium even after regular feeding is resumed. It is designed to be used when you're away from your tank for a few days, 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. For particularly large, hungry fish, such as large cichlids or loaches, you can add another feeding block to the recommended amounts see packaging for details. For fish used to eating at the surface, try breaking off a bit of the block before adding the block to your aquarium. Once the block has settled, release the remaining portion directly over the block so your fish can locate the temporary food source.