Water softeners · Filters · Reverse osmosis · Well water

Better water at home, compared by the numbers.

Softeners, whole-house filters and drinking water systems, compared on certifications, capacity and real costs. Free calculators and plain-English guides.

Size your water softener Read the guides
121+mg/L of hardness counts as hard water (USGS)
17.1mg/L equals 1 grain per gallon
NSF/ANSIthe certifications that back a filter's claims

Free calculators

Water softener size calculator Find the grain capacity your household needs. Softener cost calculator Upfront, install, salt and water costs over 10 years. Hardness converter Convert ppm, mg/L and grains per gallon.

Softener, filter or reverse osmosis?

They solve different problems. A softener removes hardness minerals, a whole-house filter treats every tap, and reverse osmosis cleans drinking water at one faucet. Many homes use two of them together.

Find the right system for your water →
SoftenerHard waterScale, spots, dry skin, short appliance life
Whole-house filterEvery tapChlorine taste and smell, sediment
Reverse osmosisDrinking waterDissolved solids and contaminants at one faucet

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