This condition occurs most often when water is very cold and then warms up while in a building's interior piping. Cold water can hold more air than warm water. Therefore, some air comes out of solution as tiny air bubbles when the water warms up. At times, the water may be so densely filled with air that the water appears cloudy. An easy way to check the cause of cloudiness is to fill a clear glass with the water, set it on a table, and watch. If the cloud rises from bottom to top, it is air escaping as the water warms. If the cloud sinks from the top to the bottom, you may have a sediment problem.