In the video, we see a close-up shot of a fish tank. The tank is filled with clear water, and there is a rock in the bottom right corner. Attached to the side of the tank is a plastic bottle with a blue tube attached to it. The bottle is filled with water and is being used as a filter for the tank. The blue tube is connected to the tank, and it appears to be circulating the water through the bottle to clean it. The video provides a detailed view of the filter system and its components.