Water softener topic 14: Why does soft water not rinse off soap?

This is in continuation of series of topics i posted on various aspects of residential water purification. Soap in its basic form is noting but Sodium hydroxide and triglycerides (essentially plant oils & / animal fats). Scientific name sodium stearate. When the hard water comes in contact with Sodium in soap, sodium molecule is displaced by calcium/magnesium which have more stronger affinity to stearate.

Because of the molecular combination, you do not feel that soapy in case of hard water. Whereas in case of softened water since calcium and magnesium are already displaced and there not much that attracts sodium stearate (contains oils and or fats) and nothing to modify the molecular structure, and hence tend to take more time to rinse off (oils and or fats) soapy water.

One of the benefits of having softener is consumption of less soap (some studies say up to 60%).and bills associated around it. Given this, consider using minimal soap (rinsing hands, washing dishes, clothes, shower etc.) i.e., than you are normally used to. There are also softeners in the market that allow you to control the softness level as well. Cheers