This question is often followed by a blank, or confused look. Not only is it a common question, it is a very valid one because it doesn’t have one simple answer. To complicate the topic further, the story is loaded with “wives tales” that started with the mother/father-in-law that knows everything. Add that to the fact that not all water softeners can be adjusted to use potassium correctly. Potassium it is less efficient per pound and more of it should be used in each regeneration.
Starting with the facts. There are two types of water that come out of a water softener: The product water or “soft water” that goes into your home; and the “drain water” that typically goes down the sewer drain (the excess brine water and all of the hardness the resin removed from the water).
At the core of all current water softeners is ion-exchange resin. Softeners come in various quantities and qualities of resin in them. (See Ion Exchange Resin Size and Type-coming soon). It is also important to note that like rechargeable batteries, resin has a limited life span. Based on water volume and chlorine levels even high grade resin could need replacing in as early as five years (8-12 years is more common). If we look at the actual makeup of the two products they are sodium chloride and potassium chloride. As each hardness ion is removed from the water by the resin, the hardness ion is substituted with a sodium ion, if salt is used, or with a potassium ion if potassium is used in the softener.
Sodium chloride is a naturally occurring mineral found in the earth and comes from underground salt mines or solar evaporation ponds. It’s the most commonly used salt in water softener brine tanks. The “regeneration process” is when the softener uses the brine solution containing sodium chloride to wash over the resin, the hard mineral ions stuck on the resin bead are replaced with sodium ions. We have found that the best, most reliable, sodium chloride is “extra coarse rock” (salt is also commonly available in blocks, crystals, pellets and cubes). Beside the fact that it’s widely available, sodium chloride often is the customer’s preferred softener salt because of the comparatively lower price and it is more efficient per pound in the water softener. Some of the softening salt pellets sold at the supermarket or home improvement stores contain a high level of impurities or water-insoluble matter. This insoluble matter can cause buildup in the reservoir or cause your softener to malfunction. Buildup in the brine tank can cause clogging of the control valve and require the brine tank be cleaned more often.
Potassium chloride also is a naturally occurring mineral (mostly mined in Canada and brought into California by railcar) and is used primarily in agriculture. It works in softeners almost the same way sodium chloride does but replaces the hard water minerals with potassium instead of sodium. Potassium chloride is an essential nutrient for human health and plays an important role in the functioning of organs, nerves and muscles. It can be found in a wide variety of foods such as dairy products, meat, fruits and vegetables. In addition, potassium chloride is important to the healthy growth of plant life. Because extracting potassium chloride from the earth is more costly than mining sodium chloride, potassium chloride is more expensive often three to four times the price. Potassium chloride is a less stable product and from time to time we see it solidify into a solid block in the brine tank. It seems to happen more often in installations where the brine tank is exposed to direct sun exposure/heat. An interesting fact on potassium chloride: When PCS Sales of Canada wanted to test market the new product to the USA they looked for an affluent area with a health and environmental conscious, they found Santa Barbara and launched their test marketing campaign here in SB. Customers often report that the water doesn’t “feel as soft” or is “less slippery” when they use potassium (this is strictly personal preference).
According to the WQA (Water Quality Association), for every grain of hardness there will be 30mg of sodium in a gallon after it has been softened. Most of Santa Barbara has been testing in the 28-32 grain per gallon range.
28 Grains x 30mg = 840mg in a Gallon (128oz)
840mg Sodium / 128oz = 6.56 mg per oz
6.56mg * 8oz = 52.5mg
An an 8oz glass of 28 grain softened water there is 52.5 mg of sodium. I have not been able to find the chart for potassium concentration, my guess is that it would be similar, please check with a health care professional for your needs or concerns.
REMOVING SALTS FROM DRINKING WATER
I have found that most people don’t drink our tap water, softener or not. If you use a reverse osmosis system it will remove the sodium or potassium in the high 90% range as well as most other contaminants. If drinking softened water is not desired, by medical, personal preference, or other reasons, you can sometimes have your kitchen cold water tap taken off of the water softener line and put on hard water, or have the sodium or potassium removed using a Sol Wave Water Reverse Osmosis System. (Fridge Filters or Brita/PUR style filters will not remove sodium or potassium and the water will still have the Santa Barbara taste).
SOFT WATER FOR GREY WATER SYSTEMS, LAUNDRY TO LANDSCAPE GREY WATER
With the drought conditions as they are, more and more people are opting to reclaim the drain water from the softener in addition to laundry to landscape grey water systems. All water softeners should be regenerating based on a meter, or volume of water being consumed in the house, or a sensor based system (like an Aqua Sensor). Time clock, or systems that regenerate based on the day of the week were banned for residential use many years ago. Be aware, you may have originally purchased a sensor model like the Culligan Aqua Sensor and the feature may have been deactivated and the system converted into a time clock. Regardless of the model periodic testing and recalibration of the system is wise to do. This is a free service from Sol Wave Water.
When I lived on the Mesa, here in Santa Barbara, the irrigation system was designed with half of the solenoids receiving hard water and the rear half receiving soft water. For five years I watered half my yard with soft water and the plants did fine. Although I have read articles online saying there will be a chloride buildup, I never noticed an adverse effect. We have several clients that have taken the drain line form the softener and, with potassium, drained there softener directly on the landscape or into their grey water tank. Again, I have never seen a negative effect. On the other hand, I would not recommend the drain water from a softener using sodium chloride be introduced onto the landscape. I did lose two Eugenia trees when my softener drain hose came out of the p-trap. It would be wise to consult with your landscaper or the city/county before doing it on your own.
We regularly connect the drain line from reverse osmosis units to grey water tanks or run the line directly out to landscape. Please feel free to call if you would like more information on our maintenance services that include the delivery of salt or potassium.
If you have not had your system calibrated in the last year now is the time… Call today!