This paper is about the realization of robot fish motion along with 3D hologram fish in an aquarium, with the augmented reality of 3D aqua holograms to attract viewers. In this new proposed concept, the animated fish video with 3D hologram is projected into a robot fish aquarium. However, this process of projecting 3D hologram fish into a robot fish aquarium may cause the overlap of the robot fish with the animated fish. To avoid this problem of overlapping, sensors play an important role. Image sensors track the robot fish movement. The proposed concept can be realized by boundary detection and optical flow algorithms, which are used to detect the positions of the robot fish. The performance of this detection algorithm was evaluated and satisfactory results were obtained. This 3D hologram with augmented reality has been successfully installed at Busan National Science Museum, Busan, South Korea.