Water Treatment · Service

Water softener installation, sized from your numbers

Ion exchange is the only household technology that actually removes hardness minerals. This page covers how a softener is chosen and sized, how regeneration is controlled, and the cases where buying one is a mistake.

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In short

What is water softener installation?

A water softener removes calcium and magnesium — the minerals that make water hard — by exchanging them for sodium or potassium on a bed of resin, then periodically flushing the collected hardness away with brine. It is the only common household method that genuinely takes hardness out of the water rather than altering how it behaves. The install is straightforward; the two decisions that matter are how the unit is sized to your hardness and your household's demand, and how it decides when to regenerate.

Triggers

Signs you need water softener installation

Soap and shampoo will not lather, and you get through more detergent than you think you should
White chalky crust building on kettles, shower heads, taps and glass shower doors
Laundry comes out stiff or grey, and dark fabrics fade faster than they used to
Spotting and filmy residue on glassware straight out of the dishwasher
Your water heater is noisier than it was, or is not lasting as long as heaters should
A certified lab test came back with hardness high enough that your health department or lab considers treatment reasonable
You moved into a house with visible scale on the fixtures and no treatment equipment at all

Seeing something not on this list? Browse water treatment problems by symptom →

The job

How water softener installation actually works

Get a hardness number you can build on

Sizing arithmetic needs a measured hardness value and, on wells, an iron reading — because iron changes the design. This is the one page-one step nobody selling softeners will let you complete independently, so complete it independently. Our water testing page covers where to get a neutral result.

Watch for: A sizing proposal built on a hardness number from the vendor's own strip test, taken in your kitchen, five minutes before the quote. It may well be right. You just have no way of knowing, and it is the input every other figure depends on.
Work out household demand, not house size

Softener capacity is consumed by hardness multiplied by water used. So the sizing method is: how many people, how much water each, times how hard the water is, equals how much hardness the resin has to handle between regenerations. Bedrooms and square footage are proxies at best.

Watch for: Sizing from bedroom count alone. It is quick, it is common, and it silently ignores the actual driver — your measured hardness. Two identical houses on different water need different units.
Choose a unit size that regenerates on a sensible rhythm

Undersized, the unit regenerates constantly, burning salt and water and letting hard water slip through at the end of each cycle. Grossly oversized, the resin sits idle so long between regenerations that the bed can channel and foul. There is a band in the middle, and a good designer aims for it.

Watch for: Being upsold on the largest unit in the range as a safety margin. Bigger is not automatically better here, and the salt and water running cost is not zero.
Metered or timer regeneration — decide deliberately

A timer regenerates on a fixed schedule regardless of use. A metered (demand-initiated) valve counts the water that has passed and regenerates when the capacity is genuinely spent. Metered control is the meaningful upgrade in most households, and it matters most where use is irregular — holidays, shift patterns, an empty house for a fortnight.

Watch for: A timer unit sold into a household that travels. It will regenerate faithfully to an empty house all week, and it will run out mid-week when everyone is home.
Decide what deliberately stays on hard water

Outdoor spigots and irrigation are normally left unsoftened — plants do not need it and you are paying salt for it. Many households also leave the kitchen cold tap on hard water for drinking and cooking. Both are plumbing decisions made at the loop, and they are awkward to change afterwards.

Watch for: Nobody raising it before the pipework is cut. The plumbing side of this is covered in detail on our plumbing prep page — raise it yourself if your installer does not.
Confirm the physical requirements before install day

A softener needs floor space for the resin tank and a brine tank you can lift salt into, a drain the regeneration discharge can reach with a proper air gap, and power. Salt is heavy and gets carried repeatedly, so the location is a decade-long ergonomics decision, not a one-day one.

Watch for: A brine tank tucked somewhere you can only reach by moving something else. You will refill it many times a year for the life of the unit, and an awkward tank is a tank that gets neglected.
Commission it and set the salt dose

Installation ends with the valve programmed to your hardness, the resin bed rinsed, the brine tank set to the right water level, and the regeneration time chosen for the small hours when nobody is drawing water.

Watch for: A valve left on factory defaults. The default hardness setting was not chosen for your water, and a unit programmed for the wrong number either wastes salt indefinitely or never fully softens.
Verify with a test, then keep checking

A hardness reading after installation is the proof the money worked. After that, a cheap strip once in a while catches a drifting valve or a spent bed long before you notice it in the shower.

Watch for: Assuming that because salt is disappearing, softening is happening. Salt can be consumed by a badly set valve without the resin ever doing its job properly.

Money

What does water softener installation cost?

A whole-home softener installed typically runs from roughly a thousand dollars for a basic unit to several thousand for a metered twin-tank system with pre-treatment, driven mainly by unit size, valve type and how much plumbing has to be added. Running costs are salt and regeneration water. Ask for the itemised quote.

See the full water softener installation cost guide — by material, size and region →

Straight answer

When water softener installation is the wrong call

Everyone else ranking for this is paid when you say yes. Here's when you shouldn't.

You have not measured your hardness. A softener with no number behind it is a guess with a monthly salt bill. Get a neutral result first; it is the cheapest step in this entire industry and it changes what you buy.
Your actual complaint is taste, smell or a specific contaminant. A softener addresses hardness. It is not a purifier, it is not a disinfectant, and it will not fix chlorine taste, rotten-egg smell or anything you are worried about health-wise. Those are different machines — see whole-house filtration or reverse osmosis.
You are on a well with significant iron or iron bacteria and no pre-treatment planned. Resin fouls. A softener placed in front of an untreated iron problem will lose capacity, then start smelling, and you will have paid for both a fouled unit and the original problem. Sequence it properly — see iron and sulphur removal.
Someone in the household is on a medically restricted sodium intake and nobody has raised it. Ion exchange puts sodium into the water in place of hardness. For most people this is a non-issue, but it is a real conversation to have with a doctor rather than with a salesperson, and potassium chloride is the usual alternative if the answer is no.
You rent, or you are moving within a year or two. The comfort benefit is immediate and genuine, but the appliance-life argument that justifies the spend plays out over many years. Portable exchange services exist for exactly this situation.
You cannot site a drain with a proper air gap. Regeneration discharge has to go somewhere legitimate. Where there is no compliant drain within reach, the install gets expensive or creative, and creative is the wrong word to hear about a cross-connection.

Your options

Types of water softener installation

Salt-free conditioner

Marketed as a softener and is not one — it does not remove hardness. Read the distinction before comparing prices.

Whole-house filtration

For taste, odour and sediment. Solves a different problem, often installed alongside a softener.

Reverse osmosis at the sink

The usual complement to a softener rather than a substitute — drinking water quality at one tap.

Iron and sulphur pre-treatment

What goes in front of a softener on problem well water so the resin survives.

Compare water treatment options side by side →

Straight answer

Can I do this myself?

A regeneration drain line pushed straight into a standpipe with no air gap is a cross-connection between your drainage and your drinking water. It is the single most commonly botched part of a DIY softener install, and it is exactly the failure mode that a permit inspection is there to catch.

Reasonable to DIY

Refilling the brine tank and keeping salt topped up
Breaking up a salt bridge and cleaning out mushy residue at the bottom of the brine tank
Setting the regeneration clock and the hardness value on the valve
Running a hardness strip periodically to confirm the unit is still working
Fitting a softener to a pre-plumbed loop with existing bypass and drain, if you are comfortable with the fittings

Call a licensed pro

Cutting new pipework into the incoming main where no loop exists
Creating the drain connection and the air gap — this is a cross-connection question and it is a code matter
Any install where a well pump, pressure tank or existing treatment train has to be resequenced
Sizing the unit and designing pre-treatment where iron, manganese or sulphur are present
Adding the electrical outlet if there is not one within reach

Before you sign

What to check when hiring for water softener installation

What hardness figure did you size this on, and where did that figure come from?

Every number in the proposal descends from this one. If it came from a strip test run by the person quoting, ask whether they will re-size against an independent lab result.
Show me the sizing working — demand, hardness, and expected days between regenerations.

A designer who has actually done the arithmetic can show it in a minute. One who picked a model off a bedroom-count chart cannot.
Is this valve metered or on a timer, and what is the price difference?

Metered control is the upgrade that matters in most households, and it is often a smaller premium than people assume.
Have you tested for iron, and does this design need pre-treatment before the resin?

Iron fouling is the most common way a correctly sized softener still fails. On well water this question is not optional.
Which fixtures are staying on hard water, and where is the branch being made?

Outdoor taps and often the kitchen cold tap. Decide before the pipe is cut, because retrofitting a branch later means opening the wall again.
What salt does this unit want, how much will it get through, and where does the bag get carried?

Salt type affects both performance and how often you will be cleaning the brine tank. The carrying route is a real quality-of-life factor over ten years.
Will you take a verification hardness reading after commissioning, and will you leave the settings written down?

The reading proves it worked. The written settings mean the next person who services it is not starting from factory defaults.

All water treatment hiring checklists →

Local pros

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Related work

Often done at the same time

Water Testing

The number every sizing decision depends on

Water Conditioner Installation

The salt-free alternative, honestly compared

Water Softener Repair

When an installed unit stops softening

Whole House Water Filtration

The other half of most treatment trains

All water treatment services →

FAQ

Water Softener Installation — questions people ask

Still have a question? Talk to our team →

Does softened water taste salty?

It should not. Ion exchange swaps hardness minerals for a small amount of sodium, and the amount depends on how hard the incoming water was — the harder the water, the more is exchanged. Most people describe softened water as tasting flatter or feeling different rather than salty. A genuinely salty taste usually means the unit is malfunctioning and brine is getting through, which is a repair symptom, not normal operation.

Why does softened water feel slippery in the shower?

Because that is what water without hardness minerals feels like. The familiar "squeaky clean" sensation is partly soap scum — hardness minerals reacting with soap and leaving a residue on your skin. Remove the hardness and the soap rinses off completely, which most people read as slipperiness. It is the softener working, not a fault, though it genuinely takes a few weeks to get used to.

Should I use sodium chloride or potassium chloride?

Sodium chloride is the default: cheaper and more widely stocked. Potassium chloride is the usual choice where sodium intake is a documented medical concern or where the discharge is going somewhere sodium-sensitive. It typically costs more and units are often programmed differently for it, so mention it before purchase rather than after. If it is a health question, ask a doctor, not an installer.

Can I drink softened water?

For most households this is not an issue, but it is a genuine question to put to your doctor if anyone is on a sodium-restricted diet — and it is why many installations deliberately leave the kitchen cold tap on hard water, or pair the softener with a point-of-use filter for drinking. Decide which you want before the loop is plumbed.

Do I still need a filter if I have a softener?

Often, yes, because they do different jobs. A softener addresses hardness minerals and nothing else. If your complaint is chlorine taste, sediment, odour or a specific contaminant, that needs filtration media chosen against your test result — which is why the two are so frequently installed as a pair rather than as alternatives.

How long does a water softener last?

Resin and control valves are both long-lived when the unit is correctly sized and the water going into it is clean. What shortens that life predictably is iron fouling, chlorine attack on the resin over years, and a valve that never got programmed for the actual water. The tank usually outlives the valve, and valve rebuilds are common well before full replacement.