Answered by Shaykh Faraz Rabbani
Sometimes a black things gets under the surface of nails even when they are clipped. Is the wudu valid if water doesn’t reach under the nails? if the dirt cannot be removed easily what should i do?
Walaikum assalam,
Dirt under the nails does not prevent the validity of wudu, as it is considered not to prevent water from reaching the skin. [Maraqi, Radd al-Muhtar]
It is from the sunna, however, to keep one’s nails trim, by cutting them every week (ideally on Friday before the prayer), or at least once every 15 days. It is blameworthy not to cut them beyond 15 days, and sinful if it goes past 40. The same applies to one’s armpit and pubic hair. [Tahtawi on Maraqi]
And Allah alone gives success.
Wassalam,
Faraz Rabbani.