For women, heaven is a glass of wine, a scented candle and a nice, soapy bubble bath. Okay, even if that isn't your idea of heaven, you still probably wash yourself, your clothes, and your dishes with soap. However, if you have hard water, this might be a lot harder than it sounds. Hard water and soap don't exactly get along. Water that's loaded with heavy mineral deposits will barely make soap lather. Worse, it leaves behind a gross soap scum ring in your washing machine or bathtub. The explanation for why resides in the chemistry between hard water and soap.
We weren't kidding when we said answer involves a lot of chemistry. Remember that class? Don't worry, we'll break it down for you.... Soap is made from oil and fat. Has been for as long as soap has been a common cleaning agent. Oil and fat work together to fight greasy stains. Here's the rub: oil doesn't dissolve in water. In order for anything to dissolve in water it needs to have a negative charge. Modern day soap has a negatively charged end, so that it gets dissolved and washed away with water. The oil itself doesn't dissolve, but the soap suspends it in the water and washes it down the drain.
Hard water contains more minerals than soft water. Minerals are an enemy to our common day negatively charged soap because hard water contains positively charged calcium ions. Positive + Negative = Neutral. The positively charged water mixes with the negatively charged soap and makes one big neutral atom, putting you right back where this all started thousands of years ago: with soap made from oils that doesn't dissolve in water. Soap that doesn't lather and leaves a soap scum ring.
While there are chemical treatments you can use, the easiest and most common answer to hard water is to install a water softener in your home. A water softener is attached to your water system and another, even more complicated, chemistry lesson takes place. Essentially it replaces the calcium or magnesium with something else, typically sodium through it's refining process. Once the water goes through the softener and the minerals are removed, the positive ions are removed. The soap is able to react with the water just the way it's meant to and the lather is back!