Cultured algae water concentration system, method for operating cultured algae water concentration system, and method for concentrating algae water containing cultured algae

The purpose of the present invention is to provide: an algae water concentration system for concentrating algae water in a culture pond into algae water containing desired sizes of algae with a single configuration, at low cost and with high efficiency; and a method for operating the system. A cultured algae water concentration system 100 is provided with: an algae water supply section 17 equipped with an algae water supply vessel 18 in which algae water from a culture pond is to be stored and a supply vessel outlet port 19 through which the algae water is to be removed from the algae water supply vessel; and an algae water concentration section equipped with a concentration vessel 1 which receives the algae water from the algae water supply section and in which the algae water is concentrated, a filter 3 which partitions the concentration vessel into upper and lower spaces and through which algae having sizes equal to or more than a predetermined size cannot pass, a vibration device 5 which can cause the filter to vibrate in the out-of-plane direction, a concentration vessel algae water inlet port 7 through which the algae water is to be taken into the concentration vessel and which is arranged below the filter in the concentration vessel, a concentrated algae water outlet port 9 which is arranged below the filter in the concentration vessel and through which algae water concentrated in the concentration vessel is to be removed, and a filtrated water discharge port 8 which is arranged above the filter in the concentration vessel and through which filtered water that passes through the filter is to be discharged.