a) There is no limit to the number of Dwaraka Shilas.
b) We can keep them separately, not mixed with the Perumal during Tiruvaradhanam. We can place them outside the inner sanctum. However, the Perumal platform must be kept clean.
c) In the Shodasha Upacharas (16 services), there is a specific service prescribed for each asana, and one must perform accordingly. There are specific Theertha-s (sacred water) prescribed for each service, such as Arghya Theertha for Arghyam and Padya Theertha for Padyam. In the Shodasha Upachara-s, Arghyam, Padyam, and everything else are included. They have set aside Sarvartha thoyam (general water) for all others except “Snanam Vastropaveetham Malayajakusume” (bath, sacred clothes/thread, sandalwood paste, flowers), Arghyam, Padyam, and Achamaneeyam (sipping water).
d) Manasika aradhanam (mental worship) is necessary. In Tiruvaradhanam, after Bhuthashuddhi (purification of elements) is complete and before offering the asanas, we must perform Manasika aradhanam, as instructed during initiation. That is, after the Sankalpam (vow) and Bhuthashuddhi, this must be done.

