The Water Softener Salt Guide for Illinois Homeowners

Which salt to buy, how much a household really goes through, how to break a salt bridge with a broom handle, and what happens the week you run out.

8 minute read · Sauk Valley, Illinois

The salt does not soften anything

Say that once and a lot of confusion goes away.

Softening happens in the other tank, on a bed of plastic beads carrying loosely held sodium ions. Calcium and magnesium carry two positive charges apiece and grip those beads harder than sodium does, so as your water passes through, the beads take on hardness and let go of sodium.

Eventually every site is occupied and the bed is finished. That is when the salt earns its keep. The valve draws a strong brine out of the salt tank and pushes it back through the resin. At that concentration the trade runs backwards, stripping the hardness off the beads and flushing it to drain. The salt is the reset button, not a treatment chemical.

The three kinds of salt, and when each is right

Rock salt

Mined from underground halite and screened, not purified. Typically 95 to 98 percent sodium chloride. The remaining 2 to 5 percent is calcium sulfate and other minerals that will not dissolve at all.

That is the whole problem with it. The insoluble material settles out and builds a grey sludge in the bottom of the tank that eventually blocks the brine pickup and plugs the injector. If you run rock salt, plan on washing the tank two or three times a year. Most people do not, and then they call somebody in November wondering why the water went hard.

Solar salt

Seawater or natural brine evaporated by sun and wind, then harvested. Around 99.5 percent sodium chloride, sold as loose crystals or pressed pellets. Far less residue than rock salt.

Its weakness is dissolving. Solar crystals go into solution slowly in cold water, and a tank in an unheated basement through a Sauk Valley February is exactly where crystals fuse to each other instead of dissolving.

Evaporated pellets

Brine that has been mechanically evaporated and recrystallized, then pressed into pellets. Between 99.6 and 99.99 percent sodium chloride, with almost nothing left to settle out.

This is the default recommendation and it is not a close call. Pellets cost more per bag than rock salt and you get it back in tank cleanings and injector clogs you never have to chase. Versions with an iron fighting or citric acid additive earn the difference on iron bearing water, though they are no substitute for an iron filter. Never put road salt in a brine tank.

How much salt a household actually uses

1. Gallons per day. Figure 60 to 80 gallons per person per day in a typical house.
2. Grains per day. Multiply gallons per day by your hardness in grains per gallon.
3. Pounds per day. Divide grains per day by the softener's salt efficiency, in grains of hardness removed per pound of salt.
4. Multiply by 30 for a monthly figure.

Efficiency is the step nobody explains. A softener regenerated on a light salt dose is far more efficient per pound than one regenerated hard. Published figures for a standard resin bed run near 4,000 grains per pound at a 5 pound per cubic foot dose, about 3,000 at 8 pounds and around 2,500 at 12 pounds.

NSF/ANSI 44, the standard for residential cation exchange softeners, only awards an efficiency rating of 3,350 grains per pound or better to units that regenerate on demand rather than on a timer. California sets its bar at 4,000. EPA's WaterSense adds a water figure: 5.0 gallons or less per 1,000 grains removed.

Worked example. Family of four, roughly 240 gallons a day, hardness of 20 grains per gallon. That is 4,800 grains a day, and at 4,000 grains per pound, about 1.2 pounds a day or close to 36 pounds a month. That is where the old rule of thumb comes from: a bag a month for a family of four on hard water.

Salt bridge: the most common softener failure

A salt bridge is a hard crust of fused salt that arches across the inside of the tank, wall to wall, with an air gap underneath. Above the bridge the tank looks full. Below it, the water sits in an empty space and never touches salt. The unit regenerates faithfully with plain water and accomplishes nothing.

Causes: humidity, temperature swings, keeping the tank topped to the lid, and loose crystals in a cold room.

To check, take a broom handle and push it straight down through the salt. If it stops on a hard shelf a few inches down and will not go further, that is a bridge.

1. Push the handle straight down through the crust in several places, working from the middle outward. Do not lever it against the tank wall and do not swing at it. The tank is plastic, and the brine well, the narrow tube in one corner, is thinner than it looks.
2. If the crust will not give, pour a gallon or two of hot water over it and wait half an hour. Hot water dissolves a bridge faster and more safely than force does.
3. Push the loose salt down into the water, then start a manual regeneration so the unit gets a real brine draw.

Prevention is easier than any of that. Keep the tank between a quarter and half full rather than brimming, use pellets, and if the tank sits somewhere cold or damp, buy salt more often in smaller amounts.

The crust on the walls, and mushing

The ring of hard deposit at the water line is far less serious: salt that came out of solution as water evaporated, plus insoluble material the salt carried in. If it is thin, scrape it and move on. A layer of sludge in the bottom, or salt gone to a wet mush, is a different matter. Empty the tank, wash it with warm water, rinse and refill. Mushing is fine salt recrystallizing into a solid mass, and it blocks brine flow as effectively as a bridge does.

Potassium chloride, honestly

Potassium chloride regenerates a softener the same way sodium chloride does, and leaves potassium in the softened water instead of sodium. That is why people use it: a household watching dietary sodium, or a discharge situation where sodium loading matters. The tradeoffs are real.

• It costs several times more per bag than evaporated salt. For most households that settles it before anything else does.
• It regenerates the resin less efficiently. Manufacturers generally advise raising the salt dose setting by roughly ten percent for equivalent capacity, so you use more of the costlier material for the same work.
• It is more hygroscopic, pulling moisture out of the air, so it bridges and cakes more readily rather than less, and it dissolves more slowly in cold water.
• It is not automatically the healthier option. Health Canada has published guidance on potassium contributed by water softeners. If anyone in the house has kidney disease or is on a potassium restricted diet, that is a question for their doctor.

One thing to weigh first: if the concern is specifically sodium in drinking water, a reverse osmosis unit at the kitchen sink removes it, and you keep ordinary salt in the brine tank for everything else.

What happens if you run out

Nothing dramatic, which is exactly why people let it happen twice. The valve keeps its schedule, draws from an empty tank, rinses the resin with water that has no salt in it, and puts a fully exhausted bed back into service. You notice within a day: soap stops lathering, spots come back on the glasses.

A short outage does no harm. Refill the tank, wait about two hours for the brine to saturate, then start a manual regeneration. It should come back completely.

A long outage is worse on some water. If your supply carries dissolved iron, resin left exhausted for weeks will foul, and iron fouling is not always reversible with a normal regeneration. That is where running dry costs you something real.

What else the salt is buying you, locally

A cation exchange bed holds other positively charged metals besides calcium and magnesium, and radium is one of them, which is why ion exchange is a recognized treatment for it. Radium occurs naturally in the deep sandstone under much of this area. Every utility below is in compliance with the federal standard of 5 pCi/L. Legal limits and health guidelines are two different lines.

When the tank is empty and the bed is exhausted, that reduction stops along with the softening. Full detection lists are on the town pages for Lyndon, Polo and Morrison.

Five minutes a month

1. Push a broom handle down through the salt. Sixty seconds, and it catches a bridge early.
2. Keep the level between a quarter and half full, adding salt as it drops toward the water line.
3. Once a year, wash the tank out and confirm the hardness setting still matches your water. Test the softened water with a strip: it should read near zero.

Liberty Water services and supplies softeners across the Sauk Valley. Where a system has to be plumbed into the main, that work is performed by a licensed Illinois plumbing contractor. Our packages page sets out what service covers.

Questions people actually ask