Picking the right water softener is an important step in the purification of your water To understand sizing, it is best to understand how it all works. What a water softener does is trade “hard” minerals in water for “soft” minerals in water. The typical trade is as calcium (hard mineral) enter a water softener it is traded for sodium (soft mineral). Inside a water softener are a bunch of chemical magnets called “ion exchange resin”. These little chemical magnets do the trading. The more chemical magnets you have in a softener, the higher the capacity is. Capacity is the amount of gallons a softener will purify before you need to recharge (regenerate) it.

Capacity of water softeners are measured in “grains” or “grain removal”. This is a chemical measurement that has been used a long time. One “grain per gallon” is equal to 17.1 parts per million. The average water in the united states has 10 grains of hardness per gallon. You can calculate the exact amount of hardness you have in your water using a water softener test kit. To calculate how much water you need to purify, multiply the number of people in your house by 80. (the average person uses 80 gallons of water per day). For an average family of 4 the calculation would look like this:

The vast majority of homes would use a 32000 grain water softener.  This would cover most homes with up to 4 people and up to two baths with showers (7 g.p.m.). On a low salt saver setting this example would regenerate about once a week.

 

See more info on capacity and salt settings here.

What type of softener do you want?

There are basic types of water softeners.  

• Timer Regenerated - These softeners regenerate based on a time clock. In our case above we would set the timer for once every 7 days and no matter how much water you use, the softener will regenerate and use about 8 pounds of salt each time it regenerated. Although a timer system is a little cheaper the salt usage is the highest of these softener types. 

• Meter Regenerated - These softeners regenerate by keeping track of how much water you actually use. During set up you simply tell the controller how many grains your softener is, how hard your water is and how many people are in your home for a reserve setting of 100 gallons per person to cover you so the system can regenerate at 2 am the next morning after your system thinks it needs to regenerate. A big advantage that meter based systems have is that if you should go out of town or have guest come and go, your softener adjusts itself to regenerate sooner for guests or later if you travel or use less water. By only regenerating when it needs to, this softener is very efficient in its usage of salt pellets. These types of system are the most popular. 

• Manually regenerated - These system do not have timers or meters on them. Instead they have a simple level that will allow you to regenerate it only when you want to. These type of softeners are perfect when you do not have a drain where you need to place the softener. You can then attach a garden hose and take it to a drain temporarily only when you need to regenerate the softener. Of course in that case you may want to get the larger capacity softeners if you want to limit the time you would need to do this. 

Removing Iron with a water softener. 

Water softeners can remove a limited amount of dissolved Iron form your water. Softeners do this because Iron likes to stick on to the surfaces of ion exchange resin.  A standard water softener contain ion exchange resin that will allow it to remove Iron if the the level is less than 4 p.p.m. A special fine mesh resin softener contains smaller bead sizes which give Iron more places to stick to. Fine mesh Water Softeners can remove dissolved Iron up to 10 p.p.m.  As the resin is regenerated the Iron is flushed off the surface of the resin and sent to the drain. The addition of an inexpensive resin cleaner will assure more complete Iron removal and will give you extended life of the resin beads.  Generally staining can be seen with iron levels as low as 0.25 p.p.m. So there is a good chance that if you have Iron staining problems, a water softener might just fixed the problem and give you soft water all with one device.  If you Iron level is higher then you may need to purchase an Iron filter for levels above 5 p.p.m.

Concerns about Sodium and Potassium in softened water. 

For those who need a sodium restriction, limit sodium intake to 3,000 milligrams per day as suggested by the American Heart Association. A teaspoon of salt contains 2,300 milligrams. Sodium helps your body maintain water balance. Too much sodium, can cause fluid buildup or elevated blood pressure. This puts extra strain on the heart and can make medications less effective. Consider replacing table salt with herbs and spices. Use fresh foods instead of processed, canned, prepackaged and convenience foods to limit the amount of salt in your diet.

All water softeners can be regenerated using Sodium chlorine or Potassium chloride. Since water softeners trade hard minerals for soft minerals that it gets from the regeneration chemical, some people with restricted Sodium diets are concerned about the levels of Sodium in their softened drinking water. The best way to eliminate this concern is to regenerate your softener with Potassium chloride pellets, The softener works the same with either type.

Each grain of hardness in your water will end out equaling  17.1 milligrams per liter of Sodium or Potassium depending on what you are regenerating the water softener with. With a low sodium diet of 3000 milligrams, average water would contain 170 milligrams per liter or water. Under this scenario you would have to drink 17 liters of water or 4.6 gallons or water per day to hit the limit.