A water level tube, also known as a water level indicator or water level gauge, is a simple device used to measure the level of water in a tank or container. It consists of a transparent tube filled with water and connected to the container.Attach one end of the tube to the bottom of the container or tank you want to measure the water level in. Make sure it is tightly sealed to prevent any leaks.Ensure that the tube is positioned vertically, allowing water to flow freely inside it.The other end of the tube should be left open to the atmosphere.