02.08.13Martha Golea

The Hidden Risks of Softened Water

The salt used to soften water causes some unexpected problems.Salt may be your friend in the kitchen, but not in the garden! The salt used to soften water causes some unexpected problems.

If you live in an area with hard water, it probably seems like common sense to have a water softening system in your home. Nobody wants spotty dishes, bathtub rings, or dull hair! But the ol’ tried-and-true water softener has a few nasty secrets. If you look at the real cost of softened water and the challenges it creates for water management, water conservation, and the environment, you might think a little differently about how you soften your water.

What’s the difference between hard water and softened water?

Water described as “hard” has a higher mineral content - usually calcium and magnesium - than ordinary water.  As more and more calcium and magnesium dissolve in the water the harder the water gets. The high mineral content makes soap less effective.  Soft water has little or no dissolved minerals, which is why you need less shampoo and soap if you soften your water.

How do you soften water?

Typical home water softeners remove calcium and magnesium from hard water by exchanging their ions for sodium or potassium. Removing the minerals makes chores easier and can make your water appliances (washing machine, dishwasher, etc.) last longer.

What are the potential problems of salt-softened water?

1) Soft water kills your plants

If you use softened water on your house plants and your landscape, over time the salt will build up in the soil and cause your plants to die of thirst. If you live in an area that doesn’t get much rainfall, the salt will not get washed out or percolate deep enough into the soil to be diluted. High concentration of salt in soil decreases oxygen levels, causes the soil to swell and become compacted. When this happens, plants cannot get enough nutrients to their roots and they die.

Two ways to tell if your plants, trees, and grass have salt stress is if they have yellow tips on their leaves or have salt rings where the water sits as it soaks into the soil. Yellow tips will be less obvious on grass because you cut off the tips every time you mow.

2) Soft water poisons soil

Salt is washed into your city’s wastewater through normal activities like showers, using the toilet and washing clothes. So even if you don’t use softened water on your own landscape, your softened water ends up in your city’s water source and is likely used to irrigate parks and agriculture. The longer an area is watered with salt-treated water, the more the soil in that area gets compacted and loses vital nutrients. Over time the high salt concentration will not only kill existing plants but also prevent new plants from growing in the poisoned soil.

3) Soft water harms the environment

In cities where water softeners are allowed, the waste water must be treated for high salt content and there is an issue of where to discharge the salt when it comes out of the water.  In places like California sometimes it’s discharged into the ocean which is expensive and can have long term effects on the aquatic environment. In other places, treated waste water is usually added to the local water source which may be a stream or lake and it will have the same detrimental effect on the fish and plants there.

4) Water softeners are water wasters!

Salt-based water softeners have some convenient benefits, sure, but they are sneaky water wasters. Advocates say you’ll save money on detergents and appliance replacements, but you will use more water with a water softener than without. Why?

First of all, because compacted soil does not absorb enough water and will runoff faster than porous soil. You will need to water more often to get the same result. Also, you have to leach the salt out of your soil to avoid killing all of your plants – and that means regularly flooding soil with enough water to push all of the salt down deeper to dilute it or flush it to the surface and away. (Again, it has to go somewhere. Your lawn may be safe but you may be involuntarily poisoning the park down the street.) While this method is effective at washing away the salt, it also washes essential nutrients out of the soil which you will have to replace with soil amendments.

Softened water isn’t recommended for drinking so many people purchase a reverse osmosis unit which wastes at least a gallon of water for every gallon it produces.

So what can you do?

There are some excellent alternatives to using salt to soften water.

First, if you use a salt-based water softener and don’t want to change, I suggest at a minimum you connect the salt water softener to your hot water line only.  This way you’ll have soft water for showers and washing clothes, but for all your cold water uses like watering plants and drinking you won’t have to worry about high sodium content.  This also dramatically reduces the amount of salt water being washed away down your drains.

Arizona State University completed a study in 2011 and discovered the most promising technology for softening water without salt  is the template assisted crystallization process. It tested four types of water softener not using salt: capacitive deionization, electrically induced precipitation, template assisted crystallization, and electromagnetic water treatment.  You can read about the study here.

In the Santa Clarita Valley of California an ordinance was passed prohibiting the use of automatic or self regenerating water softeners.  But the prohibition doesn’t mean nasty hard water for all their residents. The city offers a large variety of options for softening water without using salt. You can find information here about these alternative products.

Have you experienced a buildup of salt in your soil and wondered what is causing it? Do you know any other solutions that I didn’t mention? I’d love to hear your thoughts. Please leave a comment below or send us a message on our Facebook page: Water Bloggers. You can also learn more about water softening hazards and participate in the discussion on Ground Chat today on Twitter at 2pm ET. Just search the hashtag #groundchat to join in!



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Martha Golea

A seasoned communicator and passionate water conservationist, Martha Golea tracks projects in progress and reports on usage of new and exploratory irrigation technology and water management strategies. Martha also regularly contributes content on water management and conservation to Lawn & Landscape Magazine.




  1. Friday, 11:52 LiteracyandTech

    Ooo…I’m sure glad we didn’t install a water softener on Westwinds when we had a high mineral content!
    I’ve always known that I could learn A LOT from my “kids!” Thanks for putting this incredible information together in a format that didn’t salt my brain cells.

    • Tuesday, 6:08 Martha Golea

      Mom (LiteracyandTech) a water softener sure could have improved that awful well water, but we did just fine without one. That’s why you have so many big strong sons; to scrub the mineral rings out of the bath tub!

  2. Wednesday, 6:06 Pauli Undesser

    This article makes it very clear that softened water should not be used OUTSIDE of the home for various reasons. Agreed, outside spigots should be bypassed. However, it is written in a manner to mislead the reader into thinking softeners are the enemy and anti-scaling devices are the ultimate solution. I would like to point out that to protect property from ALL negative aspects of hardness, you need to actually remove hardness. The article does not mention that template assisted crystallization and some other anti-scaling technologies do NOT remove hardness. Furthermore, the article does not mention that product certification standards to validate performance of these devices will not be complete until later this year leaving it up to consumers to base buying decisions on potentially biased company data. It mentions the ASU study to support performance, but leaves out the detail that the study only reflects performance on gas fired water heaters, but does not address worst performance with electric type water heaters (40-60% of the US market and increasing). Lastly, the article does not mention that some anti-scaling products have severe limitations with specific water qualities. For these reasons, homeowners should understand that anti-scaling technologies may not be the ultimate answer today, but that the water treatment industry is working on performance standards and other tools to help innovative technologies become solutions in the future.

    In regards to the comment “Softened water isn’t recommended for drinking so many people purchase a reverse osmosis unit which wastes at least a gallon of water for every gallon it produces,” it needs to be noted that softened water is fine for drinking and cooking. It would be more accurate to state that many people purchase a reverse osmosis (RO) unit to improve the taste or remove other contaminants that may be in their water. Many RO systems do waste water to produce good quality water; however, there are RO units that recycle the water through the hot service lines or other methods of reclamation.

  3. Wednesday, 9:26 Martha Golea

    Pauli, thanks for your comments here and on LinkedIn, and for your professional advice. As you say, the water treatment industry is always advancing, making improvements in treatment technology all the time. It’s impressive.
    In my research, the majority of sources state that salt-softened water is not recommended for drinking, for a variety of reasons. Not just because it tastes bad. I wonder if this is something that the industry disagrees on or if salt water quality is a popular misconception.

    • Wednesday, 10:28 Pauli Undesser

      Depending on the level of hardness in your water, a softener would typically add an amount of sodium to 2 liters of water (average daily consumption) that is less than or equal to what is present in one cup of milk (122 mg), 2 slices of bread (200 mg), a baked potato (270 mg), or the tuna salad I plan to eat for lunch (320 mg). For this reason, it is shown NOT to be a significant source of sodium and calling softened water “salt water” is inaccurate. If you are in the limited population that are on a severely restricted sodium diet and every milligram counts, then potassium can be used for the softener in place of sodium.

  4. Monday, 4:05 John Koeller

    I agree with Pauli. The article is misleading and appears (to me) to be written by the propagandists from certain well-known special interest groups. First of all, the statements that emphasize salt effects upon plant health infer that people use salt brine to water plants, something that no one in their right mind would do! Furthermore, people who own and use water softeners know that softened water should also not be used to irrigate, so that, too, is another ‘straw man’ set up to scare people about softeners, in my opinion.

    I was going to also respond to the article’s references to ASU research and other ‘salt-free’ technologies, but Pauli’s statements did that for me quite clearly as follows: “I would like to point out that to protect property from ALL negative aspects of hardness, you need to actually remove hardness. The article does not mention that template assisted crystallization and some other anti-scaling technologies do NOT remove hardness.”

    By citing research done at ASU, the article’s author fails to note that alternative ‘salt-free’ technologies developed there and elsewhere (UK, Germany, and others) are useful for scale reduction, but scale reduction happens to be only one of the several reasons consumers install home water softeners. The reason softeners are installed by many consumers is for the ‘comfort’ of showering and, when compared with the problems associated with hard water, the reduced need for soap, detergents, etc. when washing clothes or other items. In particular, the ASU study authors have already stated that the technologies they investigated were applicable to scale-reduction, NOT to water softening in the traditional sense as the consumer expects.

    The article goes on to claim that softeners ‘waste water’. Yet, I see no evidence that anyone has measured the amount of such ‘waste’ and balanced it against the reduced amount of water needed for hygienic tasks and the ancillary benefits of softener use. Obviously, softeners are usually regenerated using potable water and the resulting brine is discharged to the sewer or some other receptacle. However, the reduction of water use inside the home plus the convenience and other benefits experienced by the residents, in my opinion, far outweigh the effects of an occasional brine discharge. Others (like the authors), of course, disagree.

    The key to reducing water use and salt brine discharges with this type of water treatment system is to develop a set of high-efficiency specifications that identify and qualify the ‘best of the best’ softening systems that are the most water-efficient and salt-efficient. That definitely can be done and we hope that such a specification is available very soon.

    Just to clarify, I have no financial or other business interest in the industry or the companies engaged in either producing or selling softener systems.

  5. Sunday, 11:15 Fred

    What I get from this article is that I shouldn’t water my plants with softened water. Which has been known since softened water was a thing. What this article doesn’t tell me is why softening my in home water is bad if I’m bypassing all of my irrigation lines. If my wastewater really gets piped back in to irrigate other things, then perhaps the municipalities in hard water areas should properly treat their wastewater to account for this, rather than have me foot the high cost for appliance replacement and hard water stain cleaning.

  6. Sunday, 12:50 John Koeller

    Entirely agree with you, Fred! Thank you for making the obvious statement. But, we already know that the original article was authored by the few advocates of water softener prohibitions and only presents their one point of view. Not an objective piece at all.

  7. Sunday, 2:03 Alex

    A water softener is a great idea in many cases… Anyone who lives in the Midwest where the water is liquid concrete will know that it does not take long for buildup to cause backups in pipes. Good point-out on the houseplants, and this especially goes for AQUARIUMS. If you have aquariums and water softeners, you should just quit the hobby.

    I came here and saw “hidden risks of water softeners”, sure there are some problems with them, but after my basement flooded because my pipes clogged up like a McDonald’s addict’s veins, I added a water softener and couldn’t be happier.

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