What should we do regarding a father afflicted with Alzheimer's who pays Zakat, but does not pay the minimum required amount due to his lack of awareness, and is not convinced by the correct guidance concerning Zakat, knowing that a portion of his money can be taken without his knowledge to complete the minimum required amount for Zakat?

If a father loses his mental faculties, his guardian must pay the zakat on his wealth. Guardianship falls first to the father [if he designated one before losing faculties], then to his executor, then to the judge. If there is no father [designated guardian] or executor, one refers to the religious judge to appoint a guardian. However, if there is no Sharia court or it is difficult to refer to one, his children should agree on someone to manage and preserve her wealth, because guardianship belongs to those most closely related to the incapacitated person and most capable of looking after their interests. Zakat is obligatory on wealth, even if the wealth belongs to a child or someone who has lost their mental faculties.