Why It’s Harder to Rinse Soap in Soft Water

Soap lathers better in soft water but it may be harder to rinse off. (image: Burst)
Soap lathers better in soft water but it may be harder to rinse off. (image: Burst)

Do you have hard water? If you do, you may have a water softener to help protect your plumbing from scale buildup, prevent soap scum, and lessen the amount of soap and detergent needed for cleaning. You’ve probably heard that cleansers work better in soft water than in hard water, but does that mean you will feel cleaner if you bathe in soft water? Some people report soft water makes it harder to rinse soap.

Here’s an email I received about that question:


For the first time we have a water softener in our house. After showering, I feel slippery, as though I haven’t rinsed off all the soap. Is this my imagination at work or is it harder to rinse off in soft water? Will soap which has not been rinsed off make my already dry skin drier? Is there a solution to my problem (presuming I have one)?



No, it’s not your imagination. Yes, the soap residue could cause your skin to become drier. Yes, water softeners can make it harder rinse cleaners.

Rinsing in Hard and Soft Water

Hard water contains calcium and magnesium ions. Water softeners remove those ions by exchanging them for sodium or potassium ions.
Two factors contribute to that slippery-when-wet feeling you get after soaping up with soft water. First, soap lathers better in soft water than in hard water, so it’s easy to use too much. The more dissolved soap there is, the more water you need to rinse it away. Second, the ions in softened water lessen its ability to ‘stick’ to the soap molecules, making it more difficult to rinse the cleanser off your body.

There are a few ways you can address the problem. You can use less soap, try a synthetic liquid body wash, or rinse with naturally-soft water or rainwater, which won’t contain elevated levels of sodium or potassium.