requirement to mix water and wine at mass?

[RGS]

I have noticed one of our priests pour the wine into the chalices and than adds the holy water only to one of the chalices. is this okay or should I ask him on the side after mass what he has done?
thank you for looking at my question

 

[Fr.Charles_Grondin]

The rubrics for Mass only use the singular when referring to the preparation of the gifts:

1. …the priest stands at the side of the altar and pours wine and a little water into the chalice, saying quietly…

1. …[The Deacon] hands the priest the paten with the bread to be consecrated, pours wine and a little water into the chalice, saying quietly…

The USCCB’s Norms for the Distribution and Reception of Holy Communion under Both Kinds when mentioning multiple chalices only reference them containing wine:

1. …If one chalice is not sufficient for Holy Communion to be distributed under both kinds to the Priest concelebrants or Christ’s faithful, several chalices are placed on a corporal on the altar in an appropriate place, filled with wine.

There doesn’t appear to be a liturgical requirement that water be poured into all of the chalices consecrated at Mass.