The video shows a colorful aquarium with various fish swimming around. The fish are of different sizes and colors, including yellow, orange, and blue. They are swimming in and out of the coral reefs that are placed throughout the tank. The coral reefs are of different shapes and sizes, with some resembling rocks and others resembling plants. The water in the tank is clear, and the lighting is bright, highlighting the vibrant colors of the fish and the coral. The fish are moving calmly, and there is no aggressive behavior observed.