According to the FDA, for a product to be considered "bottled water," it cannot contain sweeteners or chemical additives, and must be calorie-free and sugar-free. Flavors, extracts and essences - derived from spice or fruit - can be added to bottled water, but these additions must comprise less than one percent of the final product. Beverages containing more than the one percent of added flavor are classified as soft drinks, not bottled water.
Iron or rust in water can be found in five different forms. The two most common types are clear water iron and particulate iron. These will cause staining in your tubs and sinks, in your laundry and can even damage your hair. The other three types are iron bacteria, organic iron and collodial iron. These will result in reddish stains and may cause water to have a sulfur (rotten egg) odor or tea-colored appearance.
Filtering water involves separating mineral particles, like particulates, iron, hydrogen sulfide or other organic matter, from H2O. By passing water through a "filter bed" or "media bed", these granular particles are trapped and clean water passes through the bed.