The video shows a person cleaning the inside of a fish tank with a small brush. The person is using the brush to remove any dirt or debris that may have accumulated on the glass. The fish tank appears to be well-maintained, with clear water and healthy-looking fish swimming around. The person is wearing gloves while cleaning the tank, indicating that they are taking care to protect their hands from any chemicals or sharp objects that may be present in the tank. The brush used for cleaning is small and handheld, making it easy to reach all areas of the tank. The person is methodical in their cleaning, moving the brush around in a circular motion to ensure that all areas of the tank are cleaned. Overall, the video demonstrates the importance of regular maintenance and cleaning of fish tanks to keep them healthy and safe for the fish that live in them.