10 models to compare

Water softeners: height or flow?

Height and flow differ. Kind S-650 rates more service flow but is taller; compare both with your installation space.

Brine-tank space and servicing still matter; these fields cannot calculate household softening load.

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With no preferences selected: A. O. Smith 45,000 Grain Water Softener is one option to compare.

No hands-on testingMethod and sources

A. O. Smith 45,000 Grain Water Softener · first with a product link

Model / item: AO-WH-SOFT-450T

Height: 39 1/2 in.
Connection description: 1-inch male NPT.

What to note:

Capacity basis: 45,000 grains maximum; operating capacity depends on salt setting.

View at A. O. Smith

If you choose At least 8 gpm for service flow, the first option with a product link becomes Kind Water Systems S-650 Salt-Based Water Softener.

10 models compared; 10 have a product-page link.

The picks

5 options to compare

Compare the details that matter to your setup.

An option to compare

A. O. Smith 45,000 Grain Water Softener

Height: 39 1/2 in.

Model / item: AO-WH-SOFT-450T

Key details

Connection description: 1-inch male NPT.

What to note

Capacity basis: 45,000 grains maximum; operating capacity depends on salt setting.

Compare specs: Height: 39 1/2 in here; 64 in on Aquasure Harmony 64,000 Grains Water Softener.

Service flow: 7.5 gpmHeight: 39 1/2 inConnection description: 1-inch male NPT

See all 4 specs

Service flow7.5 gpm

Height39 1/2 in

Connection description1-inch male NPT

Capacity basis45,000 grains maximum; operating capacity depends on salt setting.

4 of 4 specs available · source checked September 26, 2026 · Source ↗
A. O. Smith · Product page checked September 26, 2026

View at A. O. Smith Compare

Service flow: At least 8 gpm

Kind Water Systems S-650 Salt-Based Water Softener

Service flow: 12 gpm.

Key details

Height: 53 in.

What to note

Capacity basis: 27,000 grains at a 9 lb salt dose.

Compare specs: Service flow: 12 gpm here; 6.5 gpm on Morton Whole Home Water Softener + Filter.

Service flow: 12 gpmHeight: 53 inConnection description: 1-inch male NPT

See all 4 specs

Service flow12 gpm

Height53 in

Connection description1-inch male NPT

Capacity basis27,000 grains at a 9 lb salt dose.

4 of 4 specs available · source checked September 26, 2026 · Source ↗
Kind Water Systems · Product page checked September 26, 2026

View at Kind Water Systems Compare

Connection description: 1-inch connection; thread not stated

SpringWell Salt Based Water Softener SS1

Service flow: 11 gpm.

Key details

Connection description: 1-inch connection; thread not stated.

What to note

Capacity basis: 32,000 grains advertised; this table does not specify a salt dose.

Compare specs: Service flow: 11 gpm here; 10 gpm on US Water Systems Matrixx Smart Metered Water Softener, 10 GPM.

Service flow: 11 gpmHeight: 57 inConnection description: 1-inch connection; thread not stated

See all 4 specs

Service flow11 gpm

Height57 in

Connection description1-inch connection; thread not stated

Capacity basis32,000 grains advertised; this table does not specify a salt dose.

4 of 4 specs available · source checked September 26, 2026 · Source ↗
SpringWell · Product page checked September 26, 2026

View at SpringWell Compare

Connection description: 1-inch male pipe thread

Morton Whole Home Water Softener + Filter

Service flow: 6.5 gpm.

Model / item: MHY

Key details

Height: 42 3/4 in.

What to note

Capacity basis: 27,200 grains at a 15 lb salt dose; the product page rounds the advertised capacity to 27,000.

Compare specs: Service flow: 6.5 gpm here; 9.9 gpm on Rheem Preferred Platinum WiFi Water Softener.

Service flow: 6.5 gpmHeight: 42 3/4 inConnection description: 1-inch male pipe thread

See all 4 specs

Service flow6.5 gpm

Height42 3/4 in

Connection description1-inch male pipe thread

Capacity basis27,200 grains at a 15 lb salt dose; the product page rounds the advertised capacity to 27,000.

4 of 4 specs available · source checked September 26, 2026 · Source ↗
Morton · Product page checked September 26, 2026

View at Morton Compare

Also compare 5

Aquasure Harmony 64,000 Grains Water Softener

Height: 64 in.

Model / item: AS-HS64D

Key details

Connection description: 3/4-inch or 1-inch NPT.

What to note

Not listed by the maker: service flow.

Compare specs: Height: 64 in here; 53 in on Kind Water Systems S-650 Salt-Based Water Softener.

Height: 64 inConnection description: 3/4-inch or 1-inch NPTCapacity basis: 64,000 grains advertised; salt dose is not specified on this product page.

See all 4 specs

Height64 in

Connection description3/4-inch or 1-inch NPT

Capacity basis64,000 grains advertised; salt dose is not specified on this product page.

Service flowNot listed by the maker

3 of 4 specs available · source checked September 26, 2026 · Source ↗
Aquasure · Product page checked September 26, 2026

View at Aquasure Compare

Comparing A. O. Smith 45,000 Grain Water Softener · Aquasure Harmony 64,000 Grains Water Softener

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The facts that differ

Choose up to three models to compare side by side.

Differences only

0 identical specs shown. Details that do not apply to these models are omitted.

Published specification comparison
Spec	A. O. Smith 45,000 Grain Water SoftenerModel / item: AO-WH-SOFT-450TNo preferences selected.	Aquasure Harmony 64,000 Grains Water SoftenerModel / item: AS-HS64DNo preferences selected.
Service flow	7.5 gpm	Not listed by the maker
Height	39 1/2 in	64 in
Connection description	1-inch male NPT	3/4-inch or 1-inch NPT
Capacity basis	45,000 grains maximum; operating capacity depends on salt setting.	64,000 grains advertised; salt dose is not specified on this product page.

A. O. Smith 45,000 Grain Water Softener

Model / item: AO-WH-SOFT-450T

No preferences selected.

Service flow: 7.5 gpm
Height: 39 1/2 in
Connection description: 1-inch male NPT
Capacity basis: 45,000 grains maximum; operating capacity depends on salt setting.

Aquasure Harmony 64,000 Grains Water Softener

Model / item: AS-HS64D

No preferences selected.

Service flow: Not listed by the maker
Height: 64 in
Connection description: 3/4-inch or 1-inch NPT
Capacity basis: 64,000 grains advertised; salt dose is not specified on this product page.

A. O. Smith 45,000 Grain Water Softener

View at A. O. Smith

Aquasure Harmony 64,000 Grains Water Softener

View at Aquasure

Compare all 10 models

— = no verified listing yet. The published order is independent of links.

All models and their decision specs
Product	How it compares	Key spec	Compare	Action
A. O. Smith 45,000 Grain Water Softener	Compared with Aquasure Harmony 64,000 Grains Water Softener: height, 39 1/2 in vs 64 in. Model / item: AO-WH-SOFT-450T	Service flow: 7.5 gpm	Compare	View at A. O. Smith
Aquasure Harmony 64,000 Grains Water Softener	Compared with Kind Water Systems S-650 Salt-Based Water Softener: height, 64 in vs 53 in. Model / item: AS-HS64D	Height: 64 in	Compare	View at Aquasure
Kind Water Systems S-650 Salt-Based Water Softener	Compared with Morton Whole Home Water Softener + Filter: service flow, 12 gpm vs 6.5 gpm.	Service flow: 12 gpm	Compare	View at Kind Water Systems
Morton Whole Home Water Softener + Filter	Compared with Rheem Preferred Platinum WiFi Water Softener: service flow, 6.5 gpm vs 9.9 gpm. Model / item: MHY	Service flow: 6.5 gpm	Compare	View at Morton
Rheem Preferred Platinum WiFi Water Softener	Compared with SpringWell Salt Based Water Softener SS1: service flow, 9.9 gpm vs 11 gpm. Model / item: RHW42	Service flow: 9.9 gpm	Compare	View at Rheem
SpringWell Salt Based Water Softener SS1	Compared with US Water Systems Matrixx Smart Metered Water Softener, 10 GPM: service flow, 11 gpm vs 10 gpm.	Service flow: 11 gpm	Compare	View at SpringWell
US Water Systems Matrixx Smart Metered Water Softener, 10 GPM	Compared with Whirlpool 18,000 Grain Compact Water Softener: service flow, 10 gpm vs 7 gpm. Model / item: MXX-100	Service flow: 10 gpm	Compare	View at US Water Systems
Whirlpool 18,000 Grain Compact Water Softener	Compared with Whirlpool 31,000 Grain Hybrid Water Softener System: service flow, 7 gpm vs 8 gpm. Model / item: WHES18	Service flow: 7 gpm	Compare	View at Whirlpool
Whirlpool 31,000 Grain Hybrid Water Softener System	Compared with Whirlpool 46,000 Grain Wi-Fi Water Softener System: different capacity basis. Model / item: WHESFC	Service flow: 8 gpm	Compare	View at Whirlpool
Whirlpool 46,000 Grain Wi-Fi Water Softener System	Connection description: Up to 1-1/4-inch plumbing; Capacity basis: 46,000 grains maximum advertised; no salt dose accompanies this value. Model / item: WHEC46	Connection description: Up to 1-1/4-inch plumbing	Compare	View at Whirlpool

A. O. Smith 45,000 Grain Water Softener

Compared with Aquasure Harmony 64,000 Grains Water Softener: height, 39 1/2 in vs 64 in.

Model / item: AO-WH-SOFT-450T

Service flow: 7.5 gpm

CompareView at A. O. Smith

Aquasure Harmony 64,000 Grains Water Softener

Compared with Kind Water Systems S-650 Salt-Based Water Softener: height, 64 in vs 53 in.

Model / item: AS-HS64D

Height: 64 in

CompareView at Aquasure

Kind Water Systems S-650 Salt-Based Water Softener

Compared with Morton Whole Home Water Softener + Filter: service flow, 12 gpm vs 6.5 gpm.

Service flow: 12 gpm

CompareView at Kind Water Systems

Morton Whole Home Water Softener + Filter

Compared with Rheem Preferred Platinum WiFi Water Softener: service flow, 6.5 gpm vs 9.9 gpm.

Model / item: MHY

Service flow: 6.5 gpm

CompareView at Morton

Rheem Preferred Platinum WiFi Water Softener

Compared with SpringWell Salt Based Water Softener SS1: service flow, 9.9 gpm vs 11 gpm.

Model / item: RHW42

Service flow: 9.9 gpm

CompareView at Rheem

SpringWell Salt Based Water Softener SS1

Compared with US Water Systems Matrixx Smart Metered Water Softener, 10 GPM: service flow, 11 gpm vs 10 gpm.

Service flow: 11 gpm

CompareView at SpringWell

US Water Systems Matrixx Smart Metered Water Softener, 10 GPM

Compared with Whirlpool 18,000 Grain Compact Water Softener: service flow, 10 gpm vs 7 gpm.

Model / item: MXX-100

Service flow: 10 gpm

CompareView at US Water Systems

10 catalog models

How the comparison works

Your choices are compared with each model’s product details. A missing or conflicting value stays unknown and cannot satisfy a choice you select. The starting order helps you browse; it does not rate real-world performance.

Source dates appear with each link below. A source date does not confirm today's price or stock.

Finder methodology Report a correction

Sources for all 10 models

A. O. Smith 45,000 Grain Water Softener: Source 1 ↗ · September 26, 2026 · Source 2 ↗ · September 26, 2026
Aquasure Harmony 64,000 Grains Water Softener: Source 1 ↗ · September 26, 2026 · Source 2 ↗ · September 26, 2026
Kind Water Systems S-650 Salt-Based Water Softener: Source 1 ↗ · September 26, 2026 · Source 2 ↗ · September 26, 2026
Morton Whole Home Water Softener + Filter: Source 1 ↗ · September 26, 2026 · Source 2 ↗ · September 26, 2026
Rheem Preferred Platinum WiFi Water Softener: Source 1 ↗ · September 26, 2026
SpringWell Salt Based Water Softener SS1: Source 1 ↗ · September 26, 2026
US Water Systems Matrixx Smart Metered Water Softener, 10 GPM: Source 1 ↗ · September 26, 2026
Whirlpool 18,000 Grain Compact Water Softener: Source 1 ↗ · September 26, 2026 · Source 2 ↗ · September 26, 2026
Whirlpool 31,000 Grain Hybrid Water Softener System: Source 1 ↗ · September 26, 2026
Whirlpool 46,000 Grain Wi-Fi Water Softener System: Source 1 ↗ · September 26, 2026

Capacity without a salt dose is an incomplete comparison

Capacity descriptions here mix advertised grain totals with ratings tied to a salt dose. You cannot compare those headlines as if they all describe the same operating setting. Whirlpool and US Water Systems provide dose-specific capacity notes for some options; other rows carry an advertised maximum without a corresponding dose.

Service-flow ratings span 6.5 to 12 gpm among the 8 products with known values. Morton Whole Home Water Softener + Filter is rated at 6.5 gpm. These are maker ratings, and their flow conditions are not automatically comparable. This guide reads the softener documentation without running household water through the systems.

Assembled height and thread wording can change the installation

Known assembled heights range from 30.25 to 64 in. That range leaves out 2 products without height values, so it cannot identify an overall shortest softener. Some dimension evidence comes from older manuals; verify current assembly dimensions and the exact configuration before purchase.

A connection described by thread size is different from a statement about supported plumbing size. Read the exact connection wording for the selected system, alongside its installation documentation. Neither height nor a flow rating supplies a household-sizing calculation.

Before you buy

Why are grain capacities excluded from filtering?

Makers give nominal, maximum and salt-dose-specific figures. Kind states 27,000 grains at 9 lb of salt; when you compare units, these bases cannot be treated as equivalent operating capacities across makers.

Does height establish the full installation footprint?

It omits other axes and service clearances. Confirm the separate brine tank, connection access and full footprint in the current manual.

Which models have gaps?

Aquasure Harmony lacks service flow; Matrixx lacks height; Whirlpool’s Wi-Fi model lacks both. Whirlpool Compact’s connection also remains unknown. Active preferences exclude a product when their required value is missing. A. O. Smith’s unit gives 7.5 GPM service flow at 39.5 in high; Kind S-650 gives 12 GPM at 53 in. Higher maker flow uses more height here. Smith suits you for the lower height with its 1 in male NPT connection. Brine-tank space and servicing still matter; these fields cannot calculate household softening load.

Does a plumbing-size limit identify a valve thread?

Rheem and Whirlpool Hybrid say up to 1¼ in plumbing. That is not a thread specification. Connection categories retain maker wording; confirm the fittings before ordering.