Is water more saltier with a softener?

[Chris50]

We are considering getting the Kinetico water softener but I read that it may actually allow more salt through - has anyone hear about this?

http://www.aquatechnology.net/reverse_osmosis.html
"An example of this interaction is that of sodium. Sodium as sulfate (Na2SO,), has a higher rejection than when present as sodium chloride (NaCl), because the divalent sulfate ion is rejected to a greater extent than the monovalent chloride ion.

When a home-use reverse osmosis system is combined with a water softener/conditioner, an increasing amount of sodium chloride(or potassium chloride if used) is allowed through the membrane. In hard water areas, where several grains of hardness are present, or where large amounts of calcium and magnesium are found, the water softener exchanges a certain amount of sodium(Click to see water softener section for specific calculations of these amounts) and these salts are then sent through the house plumbing.

"

[Andy CWS]

A softener, properly set up and working will not allow salt to come through, let alone 'more' salr. Not sure what you meant by more salt. More than what?

The sodium that a softener produces will be relative to the hardness it is removing. For that ad to make claims that (a lot) of sodium comes THROUGH the membrane is fantastic and ridiculous. Any trace amount will be so insgnificant that it would hardly be detectable in such trace amounts.

What are the issues you are concerned with?

Andy Christensen, CWS-II

[Chris50]

Thanks for your comments.
We are concerned about getting any of the salt in our drinking water because we have someone here that has hypertension and is on a strict low salt diet.

If the softener does add some salt to the water, will the Reverse Osmosis unit filter it out?

[pete c]

Still kinda new to this water treatment thing, but, as Andy says, the amount of salt making it through, if any is barely measurable trace amounts. Not enough to taste and certainly not enough to have any dietary significance. I do know that some systems will pass through measurable as well as tasteable levels of salt if you use the water during the regen cycle in the middle of the night. So just keep a few bottles in the fridge if you decide to get up at 2AM for a drink.

I do know that RO is a complimentary process to a softener system. I just bought an under the sink mounted RO/carbon system and in reading the manual, discovered this. So, I'm in the market now for a softener system myself, which is how I found this site.

[Akpsdvan]

What kind of hardness is in the water?
How many grains of hardness is there?
for every one grain of hardness removed there is 17.1 mg/l of sodium added.
Now unless the hardness is in the 20's the amount of sodium added is going to be low, and the amount of water that one intakes.. unless one is drinking gallons per day..

I feel that part of this is to sell more equipment to the home owner, nothing more.

[Andy CWS]

...for every one grain of hardness removed there is 17.1 mg/l of sodium added.

I'm not sure of those numbers. Hardness in grains is measured in calcium carbonate (CaCO3) as 17.1 ppm (mg/l) but since sodium 'over-compensates', the TDS would actually be higher than 17.1 to some degree. The TDS of softened water exceeds that of the hard water it replaces. I think, but not sure, that potassium salts would raise TSD levels even higher due to the ion exchange ratio.

I would have to do more reseach on that, but wouldn't you agree, in theory?

[Akpsdvan]

I was looking up the exchange rate of hardness and sodium..
That was the number that I was running across, and on the back of the K-Life bag there was a chart on exchange rates.... comp hardness and added sodium or potassium..
If you have a better chart could you post it?
I often get some kind of question about the amount of sodium getting added and having the right info is always better.

[EpicNole]

This may help you understand the relationship of sodium to initial harndess. Most people will never know or have any effects from the trace amount of sodium left behind in the softening process. However the facts are, without an RO system, persons on a highly restricted diet need to pay attention to their water softeners and the sodium left behind in the water! We here in FL have to deal with highly restricted sodium diets on many of our elderly customers as our municipal water averages 15gpg. We often encounter people that need to switch to potassium chloride. Potassium Chloride is awfully expensive these days but may be necessary for some folks.

Here is a cut and paste of a handout that we have for our customers. The final table is a little hard to follow in this format, but it is certainly useful in demonstrating how little sodium is actually left behind.



SODIUM IN SOFTENED WATER

Since sodium is added to water softened by the mechanical water softening process, the level of sodium may be of interest to persons on sodium restricted diets. The table below shows the amount of sodium added to softened water of varying original hardness. The harder the water is originally, the more sodium that is left behind in the soft water.

Sodium Added to Water from Cation Exchange Softening
Initial Water Hardness Sodium added by Cation Exchange Softening of Water
Grains Per Gallon (GPG) Milligrams Na+/Gallon Milligrams Na+/Quart
1 30 7.5
5 149 37
6 179 44
7 209 52
8 239 60
9 269 68
10 298 75
15 447 112
20 596 150
30 894 225
40 1,191 300


How does this sodium content of softened water compare to sodium found in common foods?

The data in the following table demonstrate the usual range of sodium in common foods.

Food Amount Mg of Sodium
Ketchup 1 tablespoon 204
Milk 2 Cups 226
Frozen Peas 1/2 Cup 295
Bread 2 Slices 322
Corn Flakes 1 oz. 260
Parmesan Cheese 1 oz. 528
Tomato Juice 4 oz. 504
Tomato Soup 1 Cup 932
Chili 1 Cup 1194
Beef Broth 1 Cup 1152


Assuming a daily intake of 5 grams (5,000mg) of sodium in food and the consumption of 3 quarts of water (used for coffee, tea, food prep, and drinking) the contribution of the sodium (Na+) in the water from a home water softening system compared to the total daily intake is minimal and can be seen in the following table.


Sodium Intake from Softened Water Compared to Total Sodium Intake
Initial Water Hardness/GPG - Milligrams Na+ Per 3 qts. Softened Water - Milligrams Na+ from Food - Total Na+ Consumed Milligrams - % of Total from Softened Water
1 23 5000 5023 0.4%
5 112 5000 5112 2.2%
10 223 5000 5223 4.3%
15 335 5000 5335 6.5%
20 447 5000 5447 8.2%
30 670 5000 5670 12.5%
40 893 5000 5893 15.2%


SODIUM-RESTRICTED DIETS

Persons who must restrict their sodium intake to 500 milligrams per day should consume water that contains no more than 20 milligrams of sodium per quart. This is assuming that most people consume about three quarts of water per day from all sources (beverages, food prep, and drinking). Twenty milligrams per quart X Three quarts = Sixty milligrams total daily from water.
The 60mg level has been suggested since the basic 500mg therapeutic diet actually contains about 440mg of sodium from food. This allows 60mg of sodium from water.
If sodium (Na+) is restricted to 1000mg per day, the upper limit for total sodium content of water is about 200mg or about 66mg per quart if three quarts are consumed.
If a water conditioner or softener is being used in a home where a person is on a sodium-restricted diet, and the water hardness is great enough that excess sodium may be consumed by using softened water, a reverse osmosis system should be utilized to eliminate excess sodium in water that is used for drinking and cooking.
If the person is restricted to a 500mg sodium diet and consumes 3 quarts of water per day, water over 2.6gpg would require the use of a reverse osmosis drinking water system. If the person is restricted to a 1000mg sodium diet and consumes 3 quarts of water per day, water over 8.8gpg would require the use of a reverse osmosis drinking water system.