Water bacterial growth/survival

It is important to point out that a small number of microorganisms surviving in the purified water system do not necessarily affect the water quality. Because of the lack of nutrients and other unfavorable conditions, the microbial growth in such waters is very slow. That provides operators with an option to maintain such systems in the state of microbial control by sanitizing them periodically rather than continuously, as long as the frequency is high enough to keep the bacterial counts at acceptable low levels. ... 

---