All water is not created equal. Although on the surface (and in the glass) it may look harmless, the water that flows through your home’s pipes and appliances may be destroying them. In many parts of the country, hard water is a perennial problem, and unless you take steps to remedy the situation in your house, you can end up with spotted dishes, clogged waterlines and a ruined water heater.
The cure for hard water is a water softener. New technology has made today’s softeners, which cost $400 to $2,000, more efficient and compact than their predecessors. But before you take the plunge, you need to understand what causes hard water and how a softener works.
What is hard water?
Water is considered hard if it contains high levels of dissolved calcium or magnesium. If you’ve ever seen drinking glasses washed in hard water, you’ve probably noticed the milky haze that won’t rinse away. That’s because hard water reacts with soap and causes a sticky scum to form on surfaces. What’s worse is the damage that hard water can inflict by causing scale to build up inside waterlines and appliances such as water heaters and dishwashers. Lines restricted by scale limit the flow of water (and reduce end water pressure), and appliances with heavy scale buildup lose their ability to function efficiently (or at all).
How a softener works
Many people incorrectly think that a water softener adds salt to water or changes its taste. Instead, a water softener removes positively charged calcium and magnesium ions from the water through an electrochemical process called ionic exchange and replaces them with positively charged sodium ions.
As water flows into the softener through a bypass valve (which lets you shut off the water to the softener only; see photo at right), it’s fed through a bed of small plastic or resin beads (see photo) that are covered with positively charged sodium ions. The positively charged calcium and magnesium ions in the water are electrochemically attracted to the resin, and as they flow over the beads, they stick, displacing the sodium ions.
As the sodium ions are gradually released from the resin into the household water, the beads become saturated with calcium and magnesium ions and must be regenerated (cleaned). Regeneration involves flushing the beads with a strong brine solution. The high concentration of sodium ions in the brine solution displaces the calcium and magnesium that has built up on the beads and replaces them with a fresh coating of new sodium ions. (This is why a water softener needs regular additions of salt.)
The sodium, magnesium and remaining brine are then dispelled out through a drainpipe set above the floor drain. (Check with your local code authority for drainpipe placement, as it may vary depending on location)
A typical regeneration process adds about 750 mg of sodium to each gallon of water — an amount the U.S. Food and Drug Administration considers to be in the “low sodium” range for commercially sold beverages. For people who are concerned about their sodium intake, resins that instead release potassium into the water exist, but the potassium chloride used to renew the resin is more expensive than ordinary sodium chloride.
Water softeners know when to recharge based on one of two methods. The first (and most basic) method uses a simple electric timer and an estimate of typical daily water usage. For example, if you know that after four days (or 96 hours) of normal water usage you run out of soft water (because the bead bed has exhausted its ability to strip ions), then you’d set the timer to recharge a few hours before this point. But changes in water usage can greatly impact this type of softener. Overnight guests or extra loads of laundry can cause a spike in water usage, and the softener will become ineffective before its programmed regeneration.
A more efficient method of regeneration meters actual water usage. These softeners have a small builtin meter that monitors how many gallons of water flow through the unit, and an attached control disc activates the various stages of regeneration . Based on the hardness of your water (which must be tested), the softener’s bead bed will be able to strip the ions out of a set number of gallons before becoming ineffective. By monitoring actual water usage, you can set the unit to recharge just before that point is reached.
Demand-based systems like this save water and salt because the softener regenerates based on actual need, not on a predetermined assumption — and they don’t waste salt and water in unnecessary regenerations.
New technology
Until recently, water softener design had changed little since the 1970s. But during the past few years, technological advances have greatly improved these machines.
For example, take the resin tank. With older units, once a softener’s resin tank needed recharging, you’d have no soft water until that task was done. But with developments such as twin resin tank technology (found on the Kinetico 2020c; see illustration), a softener can never lose its ability to create soft water — one of the two resin tanks is always available. When one tank needs to regenerate, service automatically switches to the other. The tank in service then provides soft water to the house as well as to the other tank so it can recharge with soft water. This means that all of the moving parts operate only in softened water, so they are never subjected to hard water scale buildup.
In the past, size was also a limiting factor. Older water softeners were large appliances, many with external brine tanks in addition to resin tanks. If you didn’t have a lot of extra space in your utility area, you were out of luck. But with the development of better resin material and more efficient designs, water softeners have dramatically shrunk. Some are no bigger than an average computer case, which makes them ideal for cramped installations. A unit this size can even fit under a sink, a boon if you need to supply soft water to one specific faucet or outlet.
Another limiting factor was electricity. Electronic timers, meters and motors needed a nearby receptacle from which to draw power, and in the event of a power loss, the unit wouldn’t function. The development of internal hydraulically driven power units (as with the 2020c) means that there’s nothing to plug in and nothing to reset. Like a miniature hydroelectric station, these types of softeners derive their power from the energy of the moving water. Besides being impervious to power outages, these units are ideal for locations that lack electrical service, be it under a sink, in a utility closet or even in a lakeside vacation cabin.
Installation basics
Installing a water softener is not a complex task, but if you’re not comfortable with cutting waterlines and sweating copper fittings, it’s best left to professionals. For this project, we worked with Club member John Haferman of Haferman Water Conditioning in Burnsville, Minnesota.
The first step is to install a bypass valve between the water supply and the softener. That way if the unit ever needs servicing, you can disconnect the water from the softener without having to shut off the supply to the entire house.
After the bypass valve has been installed, hooking the unit to the lines is simple. If you ever need to remove the softener (when winterizing a cabin, for example), it’s easy to detach it from the bypass valve assembly — just remove the screw and locking tab and slide out the).
Each softener has specific steps for setting the water hardness level and regeneration times, so make sure to follow the manufacturer’s directions. Then you just need to add salt and turn on the water.
Immediately run your softener through a regeneration cycle, and turn on a hot water tap to drain your water heater — remember, it’s still full of hard water. Once your softener has completed its cycle, you’ll be able to immediately enjoy all the benefits of soft water.
MORE ON THE PHOTOS
Photo 1: Minuscule resin beads are coated with sodium ions to strip away calcium and magnesium ions and make water soft.
Photo 2: A bypass valve lets you shut off the water flow to the softener without shutting down the entire house’s water supply.
Photo 3: A drain line lets the calcium, magnesium and excess brine solution flow away. Local codes will dictate placement of the discharge line.
Photo 4: A built-in water meter monitors actual usage, and an attached control disc activates the stages and times of regeneration.
Photo 5: Salt (either in block form or pellets, as shown here) is injected with water to create a strong brine solution, which then flushes through the resin tanks.
Photo 6: A typical installation will require you to cut existing water supply lines and sweat new fittings. Be precise as you lay out the new lines, and keep everything straight and level.
Photo 7: By removing the locking tab, you can slide the softener off of the bypass valve assembly.