The video shows a person's hand holding a blue object, which is being used to stir the water in a fish tank. The tank is filled with water and has green plants and fish swimming around. The person's hand moves the blue object around the tank, causing ripples and waves in the water. The fish swim around the tank, some coming close to the surface while others swim deeper. The plants sway gently with the movement of the water. The lighting in the tank highlights the colors of the fish and plants, making them stand out against the blue water.