WaterBoss Model 900 Water Softener

Checked against its certification listings: what they cover, what the maker claims, and what it costs over five years.

Water softener

Listings checked Oct. 13, 2026

Certified to

NSF/ANSI 44NSF listingchecked Oct. 13, 2026

Certified for: Hardness

Service flow: 7.5 gpm
Built for: City or well water
Regenerates: On demand

Home Depot’s price

$541

as of Oct. 13, 2026

Five years, household of 3

$758

0.2¢ per gallon

Salt included, at 10 grains per gallon

At Home Depot The maker’s page

Price from The Home Depot’s page, checked Oct. 13, 2026. The maker publishes no price. Prices change and can differ by store; Home Depot’s page is the final word.

What the listings say

Standard	Certifier	Claims	Listing
NSF/ANSI 44	NSF	Barium Reduction; Efficiency Rated; Hardness Reduction; Radium 226/228 Reduction	Read the listing checked Oct. 13, 2026

Certified for, and claimed

Certified, by a listing

Hardness

Claimed by the maker only

hardness up to 90 grains per gallon
ferrous iron up to 10 ppm
dirt and sediment

What it costs over five years

Household of 3, 240 gallons a day through the whole house. Installation not included. Salt at 10 grains per gallon (171 mg/L), an example hardness, and $9.88 a 40-lb bag (The Home Depot, Oct. 13, 2026).

Item	Replaced	Count	Amount
System, with first media	—	1	$541
Salt, 40-lb bags	A bag every 3 months171 lb a year at 10 grains per gallon	22	$217

Five-year total$758

Per gallon0.2¢

Work it out for your water

Salt and regeneration

Worked out at its efficiency-rated setting: 8,180 grains of hardness on 1.6 lb of salt, 5,112 grains a pound. At 10 grains per gallon (171 mg/L), a household of 3 would use about 171 lb of salt a year, and it would regenerate about every 3 days, sending about 2,090 gallons a year to the drain.

Salt settings the maker publishes
Salt per regeneration	Capacity	Grains a pound	Water each time
1.6 lbUsed for the cost	8,180 grains	5,112	19.5 gal
6.5 lb	23,277 grains	3,581	19.5 gal
15 lb	39,676 grains	2,645	36.8 gal

Settings from Models 700, 900 and 950 Owner's Manual (April 2025), pages 23 and 24, WaterBoss, checked Oct. 13, 2026. Less salt per regeneration gets more from each pound but regenerates more often.

The maker gives a maximum of 90 grains per gallon.

Softening water at 10 grains per gallon adds about 80 mg/L of sodium, by Nebraska Extension’s figure of about 8 mg/L a grain.

Every softener, worked out for your water

Worth knowing

WaterBoss markets it at 38,000 grains and Home Depot at 36,400; the manual's highest setting is 39,676 grains at 15 lb. The manual prints the same 19.5 gallons of water for its 1.6 lb and 6.5 lb settings. Demand-initiated, with a built-in self-cleaning filter and no cartridge. The salt figures here are at its efficiency-rated setting. WaterBoss gives no price and names The Home Depot among its stores, which showed $540.54 on Oct. 13, 2026.

Install requirements

Kind	Water softener
Rated media life	Not stated
Needs a drain	Yes
Needs power	Yes

Other whole-house systems

All whole-house systems