As per the Agama-s, the daily Tiruvaradhanam for Salagrama Perumal must be done with tirtham. The performance of Tiruvaradhanam with akshatai is a method allowed by certain traditions for certain types of worship. As Sri Pancharathra Agama specifically mentions that Perumal Tiruvaradhanam be performed with tirtham, etc., we do so. At times when Perumal is invoked in a Kumhbam, akshtai is used. Besides, there are procedures prescribed by Shaunaka Bhagavan. Since the procedures prescribed by Sri Pancharathra Agam are considered to be primary, we follow them.