My Drinking Glasses are Cloudy
This can sometimes be seen from dishwashers. It is often confusing as it can happen with both soft and hard water. Here is the expert answer.
Very high water temperatures in automatic dishwashers can cause detergent phosphate compounds to change into aggressive forms. If enough dish soil or water hardness is available, it will react with the most aggressive of these sequestering phosphates. Otherwise excessive detergent agents can actually extract elements directly from the glassware composition.
In early stages, etching appears as rainbow-colored film similar to an oil-on-water film. As etching progresses, this film changes to opaqueness, which appears similar to filming except that it cannot be removed or repaired since etching is an eating away of the glass.