There were determined in the experimental research that the longest term (18–21 days) of the E. coli and Vibrio alginolyticus surviving is characteristic for a closed model or a model with the recirculation in the superficial layer. When intensive recirculation in the full volume of model environment the concentration of dissolved oxygen is increased and the time of the surviving of condionally pathigenic microflora is increased. It is expediently to check found peculiarities in the nature conditions.
