The results of the study of the water-chemical and microbiological regime of operation of the cooling water recycling systems of TPP-25 and TPP-26 are presented. According to the results of the microbiological analysis of the additional and circulating water, the sources of microorganisms entering into its composition are classified and identified, the previously unknown function of the technology for deep water softening in an alkaline medium is established, which is proposed to be used to remove sediment-forming components from additional water. It is shown that for the fight against microorganisms immobilized on the inner surfaces of pipelines transporting circulating water and in turbine condensers, a biocidal treatment of circulating water is required. The results of the entire range of studies form the basis of the technology that allows to prevent precipitation of any nature on the heat transfer surfaces of turbine condensers.