Midification in water for Injection Storage and distribution System

Dear All Valuable Reader,

There are two storage tank for WFI Storage.The one existing Storage tank for WFI is replaced by another larger capacity tank of same MOC.
Installation and Operational Qualification is executed successfully, all the tests like Welding, chemical and microbial test are found satisfactory. the existing WFI generation, storage and distribution system is already qualified since two (02) years.

Ques: Is it necessary to cover all the sampling points after above mentioned modification ?

Here we r doing sampling as per routine basis i.e. The frequency of return and supply of storage tank are daily where as other points are covered on weekly basis.

kindly advise as per regulatory point of view.

Awaiting for your valuable suggestion.
THNX.