Ask Dr. Pete: How does hard water affect cleaning?
A product inventor, innovator, and sustainability expert, he’s the brains behind our Bio Laundry Detergent and was a founding member of The Sustainability Consortium. Last month he covered everything you need to know about reproductive toxins. This month he’s back with an in-depth explainer on how water hardness or softness affects the efficacy of your cleaning products.
How does hard water or soft water affect cleaning?
In the United States, most of the soft water locations (i.e.,water hardness levels between 5-60 ppm) are on the east coast and in northwest states. For people living in these areas, they may experience “slippery” or “slimy” water when they take showers or wash their hands. Here are the reasons and what should be done.
Soft water has much less dissolved minerals, i.e., calcium and magnesium ions in the water. As a result, most of the surfactants (i.e, soap and other types of detergents) used in the cleaning products are “freed up” from being captivated by the minerals. In skin cleansing, one may notice more lather being generated. There could be a layer of water film on the skin, which is hard to rinsed off at the end. For people who are used to hard water washes, there is always a very thin layer of mineral deposit on the skin at a microscopic level. That thin layer of mineral deposit helps keep the water from adhering to the skin and creates that “dryness” feel after rinsing off. Now with soft water, that microscopic layer of mineral deposit is no longer there, and water tends to wet and stay on the skin to form a microscopic film by itself.
What do people need to know to address this “slippery” or “slimy” feel after rinsing off? Nothing actually. Just get used to it as there is only a very thin layer of water left on the skin that causes this feeling. For washing with soft water, there is also no need to overdose the amount of soap, body wash or shampoo, as more of the active ingredients are "freed up" for cleaning action due to the low levels of mineral ions in the water.
For laundry and household cleaning using soft water, you may also consider reducing the dosage of laundry detergents and surface cleaners for the same reason.
Hard water affects many people living in the mid and southwest United States. Water hardness is determined by the level of minerals (ie. calcium and magnesium) dissolved in the water supply. The higher the mineral levels, the harder the water. Water hardness can range from being a little hard (60-120 ppm), hard (120-180 ppm) and very hard (>180ppm).
For people who have very hard water, it is a good idea to have water softeners installed for many benefits including extending the lifespan of the water pipes and faucets, as well as improved washing experiences.
Skin and hair may feel tight and itchy after taking a shower under very hard water. That is because too much mineral residue is deposited onto skin and hair and is difficult to rinse off completely. Increasing the water temperature and amount of soap and shampoo should mostly take care of this issue. Avoid using fatty acid soap bars in this case. Liquid soap and shampoo will do a much better job in hard water skin cleansing.
For laundry and surface cleaning using very hard water, the suggestions are similar. One may need to increase the water’s temperature, apply heavy duty or steam cycles from the washing machine, and increase the dosage of the laundry detergents and surface cleaners to off-set the minerals’ binding effects and prevent their redeposition to the laundry fibers and surfaces.
In addition to your bath tub and shower space, acidic cleaners may need to be applied to other hard surfaces in the kitchen and on tile floors to eliminate mineral deposits from hard water exposure.