The addition of fluoride to drinking water has greatly improved the dental health of American and Canadian consumers. Excess fluoride in water is removed by the water company using special treatment. Cloudy looking water is most often caused by air in the water. To determine if the problem is air, let a glass of water set and it should clear from the bottom to the top. In severe cases this could take up to 5 minutes for the glass to completely clear, and it may leave air bubbles around the glass.
Coffee has natural oils which can be seen occasionally on top of the coffee.
It does not come from the water used to make the coffee, but forms in the process of coffee brewing. The water contains naturally occurring calcium which remains after the water has evaporated. It is not harmful. If you use filters, maintain them carefully. They can become breeding grounds for bacteria.