Water is a natural solvent, and given the needed time and conditions, it will dissolve anything it comes in contact with. That’s why, depending on where you live, your water can contain iron or manganese, which can cause rusty-orange or black staining. It can even alter hair color. Or if you have water that has a low pH, you can see the telltale, blue-green stains. You’ll see the stains on clothes, fixtures, sinks, tubs, water-using appliances and toilets. Quite frankly, the stains can appear on anything the water comes in regular contact with. These stains are very difficult to remove, if you can get rid of them at all.