How can one pay Zakat on a small amount of money (25 Riyals) after a year has passed, given the difficulty in finding the poor, and is it permissible to pay it by offering a meal to a low-paid sanitation worker, or by purchasing a carton of water and dedicating it for the sake of Allah?

The nisab (threshold) for zakat on currency or trade goods is estimated based on what is most beneficial for the poor, whether it be the nisab of gold or silver. Zakat becomes obligatory if the wealth reaches the nisab of gold or silver and a full lunar year (hawl) passes without the wealth decreasing below the nisab.

If zakat becomes obligatory, it is to be paid from the money itself, and it is permissible to appoint someone to distribute it. It is also permissible to give it to a cleaner if their salary is insufficient to cover their essential needs.