How Whole-Home Water Softeners Work

If you live in an area with hard water, you may have been told that you need a water softener. You may wonder, “Isn’t a water softener just a glorified filter?” No, a water softener is quite a bit more complex. A basic understanding of how a water softener works can help you decide if a whole-home water softener is a good investment.

How to Select a Water Softener

If you are dealing the with hard water problems in your home, you may have decided that your best option is to buy a water softener. But if you think that buying a water softener is about as challenging as buying any other type of water filter, think again. A quick search on one of the major home improvement retailing websites will quickly reveal that buying a water softener can be a complex decision. The first thing you need to know is what size you need.
Getting the right size water softener is important for two reasons:
  • Cost. Water softeners come in a wide range of capacities and cost from several hundred to nearly two-thousand dollars. Other factors affect costs over the lifetime of the unit. Getting the right size means you get the most bang for your buck.
  • Having enough soft water. If hard water is a problem, an under-sized unit is not the solution.
What is your grain number?
If you want to soften your water, the first thing you need to know is how hard it is. If you use municipal water, you can learn this by simply asking your water provider. If you have a well, you will need to either have your water tested or buy a kit and test it yourself. Hardness is measured in grains per gallon, more commonly referred to as GPG.
By knowing how hard your water is, you have the first piece of your grain number requirement formula. The second number you need is how many gallons of water your household uses each day, on average.
If you prefer, you can use the commonly accepted average of 75 gallons per person per day. Bear in mind that if you use significantly more than this, then you may purchase a unit that is too small. If you over estimate, you may be paying more than you should for an oversized unit.
Once you have those numbers, the formula is simple: gallons per day x GPG.
For example, if two people live in a house with moderately hard water (5 GPG) and they use an average amount of water each day (75 gallons each), then the formula looks like this:
150 gallons per day x 5 GPG = 750
That is how many grains the water softener needs to remove from your water each day.
When you look at water softeners and the grain number, you will have one more calculation to perform. Simply divide the listed grain number by the amount you need removed each day. That will tell you how many days your water softener will last between recharges.
Also, don’t forget to include a buffer for high-demand periods, such as if you have guests for holidays.
While there are several important factors to consider when selecting a water softener, size is perhaps the most important one. Know your numbers and buy with confidence.