Delayed shutoff device

A delayed shutoff device comprising:

• a conduit configured to allow a fluid to flow through, wherein the conduit includes a conduit start and a conduit end;
• and
• a plug configured to:
• be placed inside the conduit at the conduit start;
• move inside the conduit from the conduit start toward the conduit end when the fluid flows through the conduit;
• and
• block the fluid flow upon reaching the conduit end, wherein:
• the conduit and the plug are configured to allow a pass-through quantity of the fluid to pass through the conduit while the plug moves from the conduit start to the conduit end;
• the conduit is configured to direct the fluid to flow to a container, the container being a toilet tank;
• the conduit end forms a seat, the plug is configured to stop moving upon reaching the seat, and the plug is configured to fit the seat upon reaching the seat imperfectly, to allow a seepage of the fluid after reaching the seat;
• and
• the pass-through quantity is larger than or equal to a preset minimum quantity.