Whole House Water Softener & Filter Systems

Softener + filter systems · Buying guide

Whole House Water Softener and Filter: Why One Tank Can't Do Both Jobs

What is a whole house water softener and filter system?

A whole house water softener and filter system is two treatment tanks installed where water enters your home. The filter removes chemicals or minerals a softener can't touch, such as chlorine, chloramine or iron. The softener then removes hardness through ion exchange, so every tap, shower and appliance gets treated water.

The two machines solve different problems. Inside a softener, resin beads trade calcium and magnesium for sodium. That stops scale in your water heater, on fixtures and in your dishwasher, but it leaves the disinfectant your city adds. A carbon filter works by adsorption and, with catalytic carbon, by breaking chloramine down. It improves taste and odor, but it leaves hardness in. Buy only one and you fix only half of what most city homes deal with.

This side-by-side shows what each tank does and needs:

Do you need both a water softener and a whole house filter?

You need both if your water is hard and also carries something a softener can't remove. On city water that is usually chlorine or chloramine. On a well it is usually iron, sulfur or acidic water. If your only problem is scale, a softener alone may be enough.

City water is disinfected on purpose, and utilities must keep a residual in the pipes. Federal rules cap that residual at 4.0 mg/L for chlorine and for chloramines (40 CFR 141.65), so some level reaches your tap by design. More than one in five Americans now get chloramine-treated water, according to the EPA. Chloramine lasts longer in pipes than chlorine, and standard carbon handles it poorly at whole-house flow rates. That is why the SoftPro Chlorine+ filters use catalytic carbon.

Chlorine matters to the softener too. It wears down softener resin over time. The SoftPro Elite HE uses 10% crosslink resin, which stands up to chlorine and chloramine longer than standard 8% resin. A carbon filter in front protects it further.

Wells are different. They carry no chlorine, but the USGS notes that private well water is not routinely tested and that homeowners are responsible for monitoring it. Your partner filter should come from a test, not a guess.

Which goes first: the water softener or the filter?

On city water, the carbon filter goes first on the main line and the softener comes right after it. That way chlorine and chloramine are removed before they reach the softener resin. On a well, the softener goes after the pressure tank, with any iron filter or pH neutralizer installed ahead of it.

Both SoftPro carbon filters are built for this spot. Water flows up through the carbon bed, which keeps the bed loose, stops channeling and adds contact time without a big pressure drop. Neither filter backwashes, so there's no drain line to run at the front of the system.

Here is the order, first to last, for each setup:

Reverse the order and the resin takes the hit: chlorine on city water, iron fouling on a well.

Which water softener and filter combo fits your water?

Match the pair to your water source. City homes pair the SoftPro Elite HE with the Whole House Chlorine+ Filter, or with the Chlorine+ & Fluoride Filter to also take out fluoride. Well homes pair the SoftPro Elite for Well Water with an iron filter or pH neutralizer chosen from a water test.

You don't need to order the two separately. The SoftPro Elite HE product page lets you add the Whole House Chlorine+ Filter or the Chlorine+ & Fluoride Filter as a package option. The SoftPro Elite for Well Water page offers a Softener + Pro Iron Filter package, sized by your well pump's flow rate.

What should you look for in a softener and filter combo?

Look for a softener that regenerates on demand with chlorine-resistant resin, and a filter whose media matches your city's disinfectant. Then check that both are sized to your home's hardness, people and bathrooms. A combo is only as good as its weakest tank, so check each one separately.

• Catalytic carbon, not plain carbon, if your city uses chloramine. Your utility's annual water quality report says which disinfectant it uses.
• Upflow design on the filter for more contact time and less pressure loss. Both Chlorine+ filters run upflow.
• No-backwash filter so the front tank needs no drain or power.
• 10% crosslink resin in a city softener, which holds up to chlorine longer than 8% resin.
• Demand-based regeneration that tracks real water use. Both SoftPro Elite models regenerate only when needed, with upflow brining that uses less salt and water than downflow designs.
• A true 1" valve so showers keep their pressure when the dishwasher runs. The Elite HE has one.
• Well-specific resin on a well. The Elite for Well Water uses fine mesh resin that also picks up some clear-water iron and manganese.
• Warranty in writing. Both Elite softeners carry a lifetime warranty on both tanks and the control valve.

How do you size a water softener and filter combo?

Size each tank separately. The softener's grain capacity comes from your water hardness and household size. The carbon filter's size comes from your number of bathrooms. On a well, any iron filter or pH neutralizer must match your well pump's flow rate, or it can't backwash properly.

Softener. Hardness times daily water use sets the grain capacity. The SoftPro Elite comes in 32,000, 40,000, 48,000 and 64,000 grain sizes. Hardness is often listed in mg/L as calcium carbonate. The USGS classes 61–120 mg/L as moderately hard, 121–180 as hard and anything above 180 as very hard. The sizing calculator does the math in about a minute.

Carbon filter. The Whole House Chlorine+ Filter comes in 1.0 cu. ft. for 1–3 bathrooms and 1.5 cu. ft. for 4–6 bathrooms. The Chlorine+ & Fluoride Filter comes in one size for 4–6 bathrooms: a 1.5 cu. ft. tank holding 1.0 cu. ft. of catalytic carbon and 0.5 cu. ft. of bone char. The catalytic carbon takes the chlorine load, which leaves the bone char free to work on fluoride.

Well add-on filter. Measure your pump's flow rate before you choose. Shut off every faucet, open a hose bib near the well pump into a 5-gallon bucket, and time the fill. The Softener + Pro Iron Filter package comes in 6–7, 8–10 and 11+ GPM versions. Don't round up.

When is a softener and filter combo the wrong fix?

A softener and carbon filter combo is the wrong fix when your water isn't hard, when your main problem is bacteria, or when a well carries heavy iron or sulfur that needs a dedicated filter. It is also wrong when you only want better drinking water from one tap. Test first.

• Your water is soft. If your report shows under 60 mg/L, which the USGS calls soft, skip the softener. A whole house filter alone may cover chlorine taste and odor.
• Bacteria shows up on a well test. Neither tank is a disinfection system. Look at UV systems, retest through a certified lab and talk to a pro.
• Heavy iron, sulfur or acidic water. Carbon is the wrong partner here. You need an iron filter, a sulfur filter or a pH neutralizer ahead of the softener.
• Fluoride on a private well. The bone char filter is not recommended for private well water. Call us before you buy anything for fluoride on a well.
• You only care about drinking water. An under-sink reverse osmosis system treats one tap for far less.
• Nitrates or other lab-flagged contaminants. Start with nitrate removal options and a lab test, not a softener.

Not sure what's in your well? The Ultimate Well Water Test Kit covers what a softener pair depends on: hardness, iron, manganese, pH and sulfur.

How we built this guide: Product specs, sizes and prices come from Quality Water Treatment's own SoftPro product pages. Public water and well statistics come from the U.S. Environmental Protection Agency (chloramine use and the federal disinfectant residual limits in 40 CFR 141.65), the Centers for Disease Control and Prevention (2022 water fluoridation statistics) and the U.S. Geological Survey (private well use and hardness classes). Your own water test decides what you need.

Whole House Water Softener and Filter: FAQ

Related: Water softeners for city water · Water softeners for well water · Whole house water filters · Iron filters · pH neutralizers · Well water filtration systems · Replacement media · Well water test kit