Whole House Water Filter and Softener System

A whole house water filter and a water softener solve different problems. A softener removes the calcium and magnesium that make water hard. A filter removes what it is built for, usually sediment and carbon-adsorbed chemicals such as chlorine and taste compounds, or iron on a well. A home with both kinds of problem usually needs both, installed in the right order. This guide explains how to tell, what goes first and what the pair costs. For a choice between the two, see the softener versus filter comparison.

Start with the problems you actually have

Hardness. Hardness is mostly dissolved calcium and magnesium, reported as calcium carbonate (University of Nebraska Extension). NDSU Extension says consumers typically notice problems such as scale and soap scum above about 6 to 7 grains per gallon. To turn a lab number in ppm into grains, use the hardness converter.

Chlorine, taste and sediment. Activated carbon removes residual chlorine, taste and odor, and many organic compounds. It does not remove hardness, nitrate, fluoride or most metals. A sediment cartridge, usually 5 micron, catches particles and protects the carbon behind it. University of Georgia and Penn State both recommend a sediment filter at the point of entry.

Iron. Clear, dissolved iron turns reddish-brown when it meets air. Once iron has oxidized, ion exchange cannot remove it, so it needs filtration. Softeners handle dissolved iron only up to a limit, and the extension sources give different numbers, so use the limit the unit’s maker rates. Above that, use an iron filter first; see our guide to the best iron filter for well water.

When you need both

• Hard city water with a chlorine taste or sediment. The filter handles taste and particles, and the softener handles scale. Our whole-house filter guide covers the filter side.
• Hard well water with sediment and a little dissolved iron. A sediment stage plus a softener rated for the iron level can cover it, if the test supports that. The well water softener guide names the softeners that publish an iron limit.
• Well water with red iron, manganese or sulfur. You need an oxidizing or iron filter before the softener. A softener alone is not enough, and the sulfur smell guide covers the options by level.

You probably need only one part if your only problem is hardness (a softener), or only taste and chlorine (a filter). If the water may carry bacteria, neither part is the answer on its own. Test first; the well water testing guide explains what to ask a lab for.

Install order: filter first, then softener

For city water with sediment or chlorine taste, the order is simple: filter first, then soften. Penn State warns that oxidized iron clogs resin, and turbid water can do the same, so the softener should not be the first thing the water meets.

For iron-heavy well water, Nebraska Extension’s multi-stage example chlorinates first to oxidize iron and kill iron bacteria, then filters the particles, then uses carbon to strip the excess chlorine, then softens. That is a designed system, and it is not the same case as clear, dissolved iron. The Mid Atlantic Water package states the order outright: iron filter first, softener second.

Two cautions. First, if your iron is clear and dissolved and you plan to let the softener handle it, Nebraska says the water must not touch air or chlorine before the softener. That can rule out some stages, so ask the installer to design the order around your test results. Second, many homes leave the kitchen cold tap unsoftened, because softening adds sodium. NDSU Extension notes that roughly 8 mg/L of sodium is added for each grain per gallon of hardness removed, so a kitchen tap that stays unsoftened avoids that sodium for drinking and cooking.

Ask for bypass valves on both parts, so one can be taken out of line for service while the other keeps running. Local code and a licensed plumber decide the connection points, pressure relief and any backflow requirements.

What the combo costs

Prices change often, so use these as ranges and check the seller for today’s figure.

Item	Range	Source
Softener hardware	About $500 to $1,500	Penn State Extension
Salt-based softener, installed	About $500 to $3,000 total	Bob Vila
Installation labor for a softener	$150 to $1,000, most jobs $500 to $700	This Old House
Carbon whole-house filter	About $450 to $600 up to $1,000 to $2,000	Brand and reseller listings
Iron filter plus 48,000-grain softener package	$3,995	Mid Atlantic Water
SoftPro Iron Master alone	$1,517 to $1,897 by size	SoftPro
Salt	$5 to $10 per 40-pound bag of sodium chloride	NDSU Extension
Softener resin service	About $100 to $200 a year for tank cleaning	This Old House
Filter cartridges	About $40 to $120 each, changed every 6 to 12 months	Contractor price estimate

Add the filter price, the softener price, installation for both, and the yearly salt and cartridge costs. The water softener cost guide and the whole house filter cost guide show the running figures in more detail. The comparison page has every model in one table.

How to choose a combo

Test first. Get hardness in grains per gallon, dissolved and total iron, manganese, pH, sulfur, and bacteria if you use a well. Ask the utility whether it uses chlorine or chloramine; the annual water quality report says which.

Match the flow rate. Each brand lists a service flow (the steady rate) and sometimes a higher peak. Compare the number you need with the one the brand quotes, and say which one you used. The flow rate calculator gives a starting figure. The Mid Atlantic package is sized for up to 10 GPM and three bathrooms. The SoftPro Iron Master needs 5, 7 or 10 GPM of well flow to backwash, depending on size.

Size the softener by grains and salt. A softener’s grain capacity depends on the salt setting. The Fleck 48,000-grain softener lists about 45,000 grains at 15 lb of salt and about 36,000 at 9 lb. The softener size calculator shows how to work out the grains you need.

Look for the right certification. Only NSF/ANSI 44 covers a softener’s hardness removal and efficiency. For filter claims, NSF/ANSI 42 covers aesthetic effects such as chlorine taste, and NSF/ANSI 53 covers health-related reductions. Check the model number in the NSF or WQA listing. The Mid Atlantic package carries NSF/ANSI 61 on its components, which covers materials, not performance. A statement that parts are tested, or that a tank is certified, does not certify the whole system for a claim.

Read the warranty. The Mid Atlantic package has 5 years on each Fleck valve and 10 years on each mineral tank. US Water Systems lists a 10-year warranty plus a one-year satisfaction guarantee on the Bodyguard.

Parts to pair

The Mid Atlantic package is the one finished combo for a well. It costs about $2,000 more than the softener alone, needs two outlets and two drains, and the ratings are the seller’s own. Its iron filter works best near pH 8, so a lower-pH well may need an acid neutralizer added, and it is not suited to wells with bacteria unless UV is added downstream. The SoftPro Iron Master is the pick if you already have a softener, or want to choose one separately. The US Water Systems Bodyguard is the one-box option for city water, but its Green Wave stage is a salt-free conditioner, so it prevents scale without softening.

Who should skip a combo

• Homes with one problem. Hardness only is a softener job; taste or sediment only is a filter job. Paying for both adds cost and salt use without fixing anything new.
• Water with bacteria and no treatment plan. A carbon filter and a softener do not make microbiologically unsafe water safe. Get the water tested and talk to a water treatment professional before you buy.
• Households that must limit sodium. Softened water adds sodium. If you have a medical reason to limit sodium or potassium, ask your doctor before choosing a softener.
• Homes on septic systems. Each softener regeneration uses about 50 gallons of water, and Penn State Extension warns that this can load a septic system. Check the regeneration setting with an installer.
• Water with iron above the softener’s rated limit. Buying a bigger softener does not raise that limit. Add an iron filter first.

Buying mistakes to avoid

• Buying by grain count alone. A large grain number at a high salt setting is not the same as the rated capacity you will use every day. Check flow and salt setting too.
• Expecting a filter to soften. Carbon does not remove hardness, so spots and scale will remain.
• Skipping the water test. Hardness, iron and bacteria each change the answer.
• Reading “lifetime” as “everything”. Warranties come with water and maintenance conditions.
• Treating a “list” price as a discount. Compare the price you are actually quoted, on the same date.
• Forgetting media replacement. Iron filter media lasts years (Katalox Light about 6 to 8 years in the Mid Atlantic filter) but not forever. Plan that cost before you buy.