How Water Softeners Work.

 Water softener systems are basically an appliance that treats incoming water to the home to remove hardness minerals (Calcium, Magnesium) present in water and provide softened water for the home to protect plumbing fixtures and water-using appliances to prevent hard water scale buildup and iron staining. Making the home run more efficiently.

Water softeners/conditioners are not the solutions to every water treatment problem. There is a myriad of water chemistry problems such as high iron, manganese, hydrogen sulfide, and low PH along with many other water problems that require different types of water treatment equipment to correctly treat the water.  The first step in determining the proper water treatment solution is a complete water analysis to determine the hardness, iron and other water chemistry issues that may need more treatment than a water softener.

Water softeners have six main components:

1. Control Valve
2. Distributor Tube
3. Water Softener Tank
4. Water Softening Resin
5. Brine / Salt Tank
6. Float Assembly

Water softener regeneration cycles:
1. Backwash
2. Brine draw
3. Slow rinse
4. Fast rinse
5. Brine refill
6. Service

Water softeners have to run/regenerate at some point to rinse off the hardness minerals the resin has collected and restore the sodium charge on the resin beads.  The regeneration cycles shown above are the most commonly used but may vary in the sequence depending on the particular water softener and manufacturer.  When not regenerating a water softener is normally in service mode.

Ion Exchange Process:  Sodium Chloride or Potassium Chloride (Water softener salt) is used to regenerate the water softener resin beads during the brine draw cycle. Sodium or Potassium displaces the hardness minerals the resin has collected during the service cycle and the hardness minerals are flushed to the drain.

Resin Regeneration Process

Water Softener Resin Comes In Many Color Variations

Polystyrene Water Softener Resin

Every water softener has a given amount of "capacity".  The amount of resin in the softener tank and size of the softener tank determine the total capacity and how many gallons of water can run through the water softener before it has to regenerate.
For example, a 9x48 water softener tank will have about 30,000 grains of capacity (1 cu ft of resin) and a 10x54 tank is about 45,000 grains of capacity (1.5 cu ft of resin).  Single tank water softeners, such as the Fleck 7000 above (Blue Tank), are factory set to regenerate at 2 o'clock in the morning (This is referred to as delayed regeneration) and takes anywhere from 60 minutes to over 2 hours for a complete regeneration cycle depending on the capacity and size of the water softener. A certain amount of resin is always left out of the total equation to have a little extra capacity on days with heavy water usage. This is referred to as the "Reserve". Typically one full day of water use is left as the reserve.


Older water softening systems operated on a "Time Clock" basis

Fleck 5600 Valve with a 12 Day Time Clock

and ran a certain number of days per week based on how many pins were set for days to regenerate. Time clock systems have 6 to 14 pins that determine how often it runs/regenerates.  These time clock model water softeners were very inefficient and frequently ran out of softened water when the capacity was exceeded. Which was usually on weekends when we all use 2-3 times the water than during the week. When a water softener runs out of capacity the resin is exhausted of softened water causing hard water to service. With a time clock water softener, there needs to be at least one day's water usage left in reserve to prepare for those heavy usage days. With more modern water softeners reserve capacity is not as important because they are constantly metering the water usage and adjusting the regeneration cycles to accommodate the changing water needs (depending on the manufacturer and model).

Modern water softening systems regenerate on gallons used and are much more efficient as they only regenerate when needed and tend to have better consistency of softened water.
There are basically three types of water softeners "Cabinet Models", "Single Tanks" and "Twin Tanks".  A single tank water softener refers to any water softener with one softener tank and a salt tank.  This may be one as shown at the top of this article (Fleck 7000) or what is referred to as a cabinet model (Shown here on the right) where the water softener system is built into the salt storage tank. Cabinet model water softeners tend to be the least expensive, and are installed by many DIY'ers but also tend to only last 3-7 years so you get what you pay for with this style softener.  They also tend to be very inefficient at removing iron from well water.

An even more efficient option for your water softening system is a "Twin Tank" water softener as 

Twin Tank Water Softener

shown here. This style water treatment system actually has two water softener tanks.  One tank is in service (supplying soft water) while the second tank is in standby.  This type of water softener is a true on-demand water treatment system. When one tank becomes almost exhausted of softened water it regenerates immediately and switches to the standby tank that goes into service. Twin Tank softeners normally regenerate during the day when water is being used.  Twin Tank systems use a portion of softened water from the second tank to clean the tank that is being regenerated so they tend to be very efficient at salt usage, iron removal, supply the best quality water, the most consistent quality of softened water and have fewer service issues because they are regenerating with clean/soft water.

For the best, durability, serviceability, reliability, and longevity and quality of water I recommend a separate water softener and brine tank system.  A separate water softener and salt storage tank can last well over 20 years.  If you decide to install your own water treatment system it pays to consult with a local plumbing supply house or local water treatment company that sells "cash and carry" water treatment systems, (NOT the box stores).  They can be a valuable resource to help you choose the proper system, setting it up, future technical/service support and test your water to find the best water treatment system to treat your water.  Having a water analysis done by an independent water testing lab is also a good idea.  An independent lab can test for bacteria, arsenic, lead and other concerns that a plumber or even a water treatment company would not normally do.  A thorough water analysis from a licensed lab can be a useful reference for the future also.  If you seek help from a professional water treatment company be sure to check them out thoroughly online.  Angie's List, Google Reviews, Yellow Pages, Yelp and various other sites can be a valuable resource to check their work, reviews and customer satisfaction.  There is a lot of advice online from so-called water softening sites and experts but I have found much of the information to be very misleading and quite often just uninformed advice from people that have never been in the water treatment business.

I hope this information and future blog articles can assist you in your search for the proper water treatment system for your home and family.  If you do choose the proper water softener system for your needs and maintain it properly there is a good possibility of it lasting 20 years or more.


I Wish You Good Water and Good Days!

R.J. DeChene
The Water Softener Blog


More information is available regarding topics of this blog in the links below:

How Softeners Work - YouTube

Water Softener Facts

Wikipedia - Water Softening

Whirpool - Water Softener Basics

Water Softener Salt

PSU Extension - Water Treatment