Three days before Nyepi, Balinese new year is celebrated a melasti must be performed. Melasti, according to the ancient scripture of Sundari Gama and Swamandala is “melasti ngarania ngiring prewatek dewata anganyutaken laraning jagat, papa klesa, letuhing bhuwana, amet sarining amertha ring telenging segara“. In English this sentence means “Melasti means to follow the deity in the purpose to drift away impurities, miseries and poor mundane elements and take tirtha amertha, or holy water of life in the sea”.
For community of which village is away from the beach, like at mountain range, melasti can be performed to lake, river other sanctified springs in the vicinity of the village. Since the concept regularity and conformity is unknown in Balinese culture the performance of melasti is adjusted to the local concept of desa, kala and patra (place, time and circumstance) so every region has its own characteristic and the term melasti varies to some regions like mekiyis, melis or mapeningan. There is no authoritative scripture that gives an explanation on how the melasti ritual is conducted. So its performance is mostly based on drsta or tradition that has been believed and practiced from time immemorial.

Melasti conducted in relation to celebration of Nyepi Day is commenced by carrying all pratimas (hallowed effigies of deity) to Bale Agung pavilion in village temple. The pratimas are assembled there and given a set of offering then carried to the sea or springs nearby. There are also those that do not assemble in advance, but waiting on the street and then depart together to the beach in a procession.
Melasti procession to the sea or spring involves all community members. Children and adolescences march neatly while bringing along the long pennant, spear and ritual umbrella while women balance offerings and other ritual paraphernalia. Meanwhile, adult men carry jempana or sedan chair of the effigies and many kind of hallowed representations like barong and rangda. During the passage, the temple priests chant holy hymns that accompanied by bleganjur gamelan orchestra played in fast rhythm as if it meant to provoke the enthusiasm of the devotees. For the devotees who live away from the beach or springs, they do the melasti procession by truck or other vehicles. While, there are also some executing it on foot and the pratimas are not carried on the head or shoulder, but put them into a sort of cart then pushed by devotees alternately. This pilgrimage does not make the devotees feel tired it is a show of their faith and loyalty to their deity.

On arriving at beach or spring, after the pratimas are abode on the position prepared, the ritual is commenced by performing mecaru or exorcism rite as symbol to purify the location and neutralize the power of bhuta kala in order the ritual will accomplish flourishingly. Then, continued with executing puja wali, or the culminating agenda to the Almighty God along with His manifestations and particularly to Lord Varuna as the master of the sea, resource of holy springs. Having completed the puja wali, it is resumed with ngamet amertha (taking holy water) in the sea while putting sesaji pekelem (offerings) equipped with a white duck and chicken that are thrown away alive into the sea. When the procession of taking holy water is over, devotees perform worship en masse and concluded with nunas tirtha amertha (invoking holy water) that sprinkled three times on the head, gulped down and washed away to the face for three times.
After the worship, the melasti ritual ends. All pratimas then carried back to Bale Agung escorted by devotees and nyejer (stand by) there for one day and entertained with offering and sometimes with sacred dance. Tirtha Amertha taken from the sea is placed on special spot to be re-used on the tawur and pangrupukan rituals. The tirtha amertha is sprinkled at home and village territory as symbol of purification and getting rid of any impurities.