Brahma Yagyam is one among the Panchamaha Yagyam. Brahma Yagyam is a daily recitation of those Vedic lessons that we have learned to ensure we do not forget them, to the best of one’s ability. It must be done without fail.
At a minimum, one must learn Purusha Suktam for daily recitation. Those who have done Veda adhyayanam, will recite one prashnam every day. Those who have undergone upanayanam perform this as soon as the adhyayanam commences. Since this is a Nitya Karma, it can be performed only as long as one’s wife is alive. Since this is a Yagya, a householder loses the capability to perform this after the ascension of one’s wife to the eternal abode.
Householders need not perform Samita Dhanam. Samita Dhanam is Samit+Adhanam, meaning offering of Samit to Bhagavan through homam/agni (ritual). It is a duty of the bachelors (Brahmachari)
The mandatory Nitya Karam-s for a householder besides Sandhyavandanam, Brahma Yagyam, and Tiruvaradhanam are – Vaishvadevam, Devarishi, Kandarishi, Ptiru Tarpanam-s, Adhara Shakti tarpanam, etc. Aupasanam is another mandatory Nitya karma.