To make clear ice we recommend using distilled water, boiled water, or water that comes out of a reverse-osmosis (RO) system. It may not come out perfectly clear but at least the ice will not appear cloudy. If you are looking to making clear ice it is more about the method of freezing than the water. The cloudiness in the H20 is caused by the O being trapped in the H. Alcademics has some cool tricks on how to control the freezing proess so all of the air in water is expelled, leaving your ice clear.