The research goal was to develop an improved water purification technology for public reservoirs by adding the vibrocavitation purification before a reagent method with sodium hypochlorite, produced via electrolysis of salt. The main tasks of the research include the determination of vibrocavitation treatment efficiency and the development of a new low-frequency vibration resonance cavitation process for water purification, as well as equipment for this process. A vibroresonance method supporting the intensity of spatial displacements of cavitation exciters was developed on the basis of the theory of cavitation fields in liquids. When using this method it was possible to establish the boundary conditions for stable support of the cavitation field created by low-frequency vibrations. The developed method is based on the formation of high intensive cavitation fields in liquids by vibratory decks. The advanced technological scheme of water purification for pools and public use reservoirs is proposed, which includes addition of resonance vibrocavitators to a closed circulation cycle of water purification by the reagent method.