About CentsPerGallon

What Every Gallon of Filtered Water Really Costs You, Filters and Membranes Included

Whole-house, reverse osmosis, under-sink, pitcher and shower filters compared on what each gallon costs once the replacement filters and membranes are counted. Every price, rating and certification line comes from the maker's own pages, with the date it was read.

Who writes here

Ruth Marchbank writes the water filter guides here. She takes each filter's price, replacement-cartridge price and rated capacity from the maker's own pages, works out what every gallon of filtered water costs you, and dates every figure. You see the cost of year two, not just the price on the box.

How we research

Every CentsPerGallon article cites its sources, listed under "Sources" at the end of the page, and the facts in it are checked against those pages before publishing. An editor reads and approves every article before it goes live.

Corrections

Found a mistake? Email [email protected] with the page address and what is wrong. We fix confirmed errors.