Hard water vs. Soft water

21 views

My parents got a water softener installed in their house a couple years back. Every time I go visit and shower there I feel slimy from the water. I hate it. They love it, good for them. But I’ve always wondered what causes that slimy feeling from the soft water. My limited understanding is that hard water contains more minerals than soft water. Is that accurate? How does that cause the slimy feeling of soft water? I’d love to understand the science behind it. Thanks!

In: 11

Following! I hate hard water which is usually what we have. My daughter has showered at my parents recently and said she hated their soft water. I know we will probably never have soft water again but I really want to shower at their house now lol

Hard water in this usage contains lots of calcium and magnesium.

Water softeners use an ~~iron~~ ion exchange resin to absorb calcium and magnesium and replace it with sodium.

Soaps and detergents stick to your skin better with soft water than in hard water.

[More details](https://www.scientificamerican.com/article/how-do-water-softeners-wo/)

Edit: curse you autocorrect!

Hard water has dissolved minerals, like calcium and magnesium, in it. Soft water had much less.

If you have hard water, you’ll find it necessary to clean and descale things like coffee makers, kettles, and dishwashers frequently, otherwise the build up inside can either make them operate ineffectively, or not work at all. However, I worked for a place that sold water softeners, and the complaint that people felt “slimy” was common.

We believed that the microscopic particles in the hard water make it feel like you’re ‘scrubbing’ your skin, while the soft water without them feels ‘slimy’ by comparison.

I assume (/hope) you mean a slimy feeling when using soap in the water? I can answer that, but if it’s the water itself then I have no idea.

For sliminess with soap, your understanding about minerals is indeed accurate. Water softening is the removal of metal cations (positively charged atoms/molecules) from a hard water source. Soap particles are attracted to charged particles/surfaces. Hard water is super effective at rinsing soap off your skin because soap particles are attracted to the charged mineral ions in it – the stream of water acts almost like a vacuum that actively sucks soap off the skin.

The lack of these charged particles in soft water makes it significantly harder to wash soap off. Your skin is lightly charged, and in the absence of other charged particles or surfaces, soap will stick to the skin. Not only is soft water much less effective at removing soap, the soap particles are also clinging on to your skin. This means getting soap off in soft water is probably going to require both a lot more water and a lot more physical effort than what you’re used to = a noticeable slimier shower experience.

Yes, hard water contains more minerals such as calcium and magnesium. A water softener will replace those positively charged ions (cations) with other cations such as sodium or potassium. That sliminess you feel is the sodium ions sticking to your skin.

Soft water, water low in minerals, does not feel slimy.

A water softener tank is full of tiny polymer beads called “zeolite.” They are about the consistency of medium-fine sand. *(Speaking from experience, if you see what looks like sand coming out of your faucet, there’s a problem with your softener: one of the very fine screens used to keep the beads in the tank has been perforated.)*

When you use water, it flows through the bed of zeolite, and ions of calcium and magnesium, present in the hard water, are replaced with sodium ions.

Eventually, the zeolite beads are depleted of sodium ions, so the water softener must be “regenerated.” It’s kind of like a washing machine cycle where the beads are first reverse rinsed to get rid of any particles that came in the water line, then in a slow process brine is pulled from an adjacent tank where there is a mixture of salt pellets and water. The brine flows very slowly through the bead bed, removing hard water ions and replacing them with sodium ions, and to the drain. Once the brine cycle is done (1-2 hours), the beads are once again rinsed to get rid of any brine in the tank. Then, the automatic valve returns to normal and you get soft water in your house again.

Some softener companies like Culligan take your bead tank on their truck back to a central location where the brine rinse takes place. This allows them to have more control than you would on the brine and stuff, reducing the amount of salt water that is discharged into the ground or the sewer system. As one might imagine, salt water never really goes away, unless you happen to live in a place where your sewer plant discharges its treated water into the ocean, so water softeners are not the best thing for local water supplies. Many inland water agencies in southern California now discourage or prohibit the use of softeners, even though our water is relatively hard in some areas.