The video shows a group of fish swimming in a tank. The fish are of different sizes and colors, with some being darker and others lighter. They are swimming around in different directions, and some are swimming towards the camera while others are swimming away. The water in the tank is clear, and the fish are moving smoothly and gracefully. The tank appears to be well-maintained, with no visible debris or algae. The fish seem to be healthy and active, and the overall scene is peaceful and calming.