Every Water Softener, Side by Side
What this is
Every unit below is specced from its manufacturer's own documentation, including the rated capacity at each salt dose, not just the marketing number on the box. Sort and filter, then click any model for its full spec sheet and source.
| Model | Type | Capacity | Salt/regen | Flow | Certifications | Warranty | Price | |
|---|---|---|---|---|---|---|---|---|
| SpringWell SS+ Salt-Based Softener | salt-based | 80,000 gr | — | 20 GPM | — | Lifetime on tanks, valves, fittings and housings | $2,678 | Check price |
| SpringWell SS4 Salt-Based Softener | salt-based | 48,000 gr | — | 13 GPM | — | Lifetime on tanks, valves, fittings and housings | $1,785 | Check price |
| SoftPro Elite Smart HE 48,000 | salt-based | 48,000 gr | — | 15 GPM | NSF/WQA/ANSI claimed on page (no standard number cited) | Limited lifetime on control valve and essential components | $1,457 | Check price |
| Aquasure Harmony AS-HS48D | salt-based | 48,000 gr | — | — | — | Extended warranty with registration (baseline not stated, retailers cite 5-year limited) | $630 | Check price |
| GE GXSH45V | salt-based | 45,100 gr | 17 lbs | 9.5 GPM | NSF/ANSI 44, NSF/ANSI/CAN 372, WQA CSA B483.1 | 1 yr parts/labor, 3 yrs electronics, 10 yrs resin tank | $586 | Check price |
| A.O. Smith AO-WH-SOFT-450T | salt-based | 45,000 gr | 18.75 lbs | 7.5 GPM | Efficiency rated per NSF/ANSI 44 | 5 yrs parts/electronics, 10 yrs media tank, valve and brine cabinet | — | Retail only |
| Rheem Preferred Plus RHS42 | salt-based | 42,000 gr | 16.3 lbs | 9.9 GPM | — | 1 yr parts/labor (extendable to 5), 3 yrs electronics, 10 yrs tanks | $589 | At The Home Depot |
| Whirlpool WHES40 | salt-based | 40,000 gr | 15.5 lbs | 8.5 GPM | NSF/ANSI 44, NSF/ANSI 372, WQA CSA B483.1 | 1 yr parts/labor (5 yrs with registered cleaner use), 3 yrs electronics, 10 yrs tanks | — | Retail only |
| GE GXSH40V | salt-based | 40,000 gr | 15.1 lbs | 9.5 GPM | NSF/ANSI 44, NSF/ANSI/CAN 372, WQA CSA B483.1 | 1 yr parts/labor, 3 yrs electronics, 10 yrs resin tank | $569 | Check price |
| A.O. Smith AO-WH-SOFT-350 | salt-based | 35,000 gr | 15 lbs | 7.5 GPM | Efficiency rated per NSF/ANSI 44 | 3 yrs parts/electronics, 10 yrs media tank and brine cabinet | — | Retail only |
| SpringWell SS1 Salt-Based Softener | salt-based | 32,000 gr | — | 11 GPM | — | Lifetime on tanks, valves, fittings and housings | $1,607 | Check price |
| SoftPro Elite Smart HE 32,000 | salt-based | 32,000 gr | — | 10 GPM | NSF/WQA/ANSI claimed on page (no standard number cited) | Limited lifetime on control valve and essential components | $1,367 | Check price |
| Aquasure Harmony AS-HS32D | salt-based | 32,000 gr | — | — | — | 5-year limited (per authorized retailer, registration required for extension) | $540 | Check price |
| Rheem Preferred RHS32 | salt-based | 32,000 gr | 14.1 lbs | 7.9 GPM | — | 1 yr parts/labor (extendable to 5), 3 yrs electronics, 10 yrs tanks | $489 | At The Home Depot |
| Whirlpool WHESFC Pro Series Hybrid | salt-based | 31,000 gr | 13.4 lbs | 8 GPM | NSF/ANSI 42, NSF/ANSI 44 | 2 yrs parts/labor, 3 yrs electronics, 10 yrs tank | $779retailer | At Lowe’s |
| Whirlpool WHES30 | salt-based | 30,000 gr | 13.1 lbs | 7.3 GPM | NSF/ANSI 44, NSF/ANSI/CSA 372 | 1 yr parts/labor (5 yrs with registered cleaner use), 3 yrs electronics, 10 yrs tanks | — | Retail only |
| SpringWell FS1 FutureSoft Salt-Free Conditioner | salt-free | — | — | 12 GPM | — | Lifetime on FutureSoft units | $1,785 | Check price |
| Aquasana SimplySoft Salt-Free Conditioner | salt-free | — | — | 7 GPM | — | 10-year limited + 90-day satisfaction guarantee | $879 | Check price |
Specs read from manufacturer pages. Each unit's page lists its source and check date. “—” means not yet sourced, never guessed.
Want the shortlist rather than the whole chart? The best water softeners by measurable axis picks a winner for price per grain, iron limit, capacity and documentation, each with the denominator it was judged against.
Not sure what capacity to look for? Size your household first. It takes 20 seconds and filters this table to units that fit.
How to read this chart
The capacity column is the figure to treat most carefully. A softener rated at 80,000 grains reaches that number only at its maximum salt dose, and running any unit at maximum salt is the least efficient way to own one. A metered head run at a moderate dose typically delivers a good deal less capacity per cycle and uses noticeably less salt doing it, which is why two units with the same headline number can cost very different amounts to run. Size on the capacity you need per week, then look at the salt column to see what reaching it costs.
The type column matters more than the price column. 2 of the 18 units here are salt-free conditioners, which do not remove hardness minerals at all. They change how scale forms rather than taking calcium and magnesium out of the water, so they leave no sodium behind, need no drain and use no salt, but a hardness test after installation reads the same as it did before. If you want the slippery-water, spot-free-glassware result people mean by soft water, those units are not what you are shopping for, and the full comparison of the two approaches is worth ten minutes before you spend anything.
Blank cells are not oversights. Every figure in this chart is read from the manufacturer's own documentation and dated, and where a maker does not publish something we leave it empty rather than borrowing a number from a retailer listing or a review site that did not measure it either. That policy is the reason the chart has holes in it, and the holes turn out to be some of the most useful information here.
What this category publishes, and what it does not
Across all 18 units, here is how completely each specification is documented. The pattern is consistent: the numbers that sell a unit are published almost everywhere, and the numbers that let you check a claim or compare running costs are the ones that go missing.
| Specification | Published | Why it matters |
|---|---|---|
| water per regeneration | 7 of 16 | matters on a septic field, where discharge volume is a design limit |
| salt per regeneration | 9 of 16 | the number that sets your running cost |
| iron tolerance | 11 of 18 | the single specification that decides whether a softener survives well water |
| maximum hardness | 11 of 18 | tells you whether the unit is rated for your water at all |
| price | 13 of 18 | left to the retailer by some manufacturers, which makes comparison harder |
| regeneration type | 13 of 16 | a metered head regenerates on water used, a timed head on a clock regardless of need |
| dimensions | 15 of 18 | determines whether it fits the space you have |
| service flow rate | 16 of 18 | decides whether two showers can run at once without a pressure drop |
The worst-documented specification in the category is water per regeneration, published on only 7 of 16 applicable units. Aquasure, Rheem, SoftPro and SpringWell all omit it. It matters on a septic field, where discharge volume is a design limit, so its absence is not a detail.
Ranked by how much of the applicable spec set each maker actually publishes, GE documents 16 of 16 figures across its units, and Aquasure documents 5 of 16. Price and documentation are not related the way you would expect in this category, which is the single most useful thing this chart shows.
Certification follows the same pattern. 9 of the 18 units here cite a third-party standard such as NSF/ANSI 44, which tests the capacity claim rather than taking the manufacturer's word for it, and 9 cite none at all. An uncertified unit is not necessarily a worse one, since certification costs money and some makers decline to pay for it, but it does mean the capacity number on the box has been tested by the company that wants to sell it to you and by nobody else. Where you are choosing between two units at similar prices and one carries a certification, that is a real difference rather than a marketing one.
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Prefer to start from a manufacturer you already know? Each brand page lists every unit it makes with the same verified specs.