Guides
Home water guides
What softeners and filters cost and what they fix, what the numbers on a water report mean, and how to test your own water. Each guide is built from U.S. Environmental Protection Agency (EPA) and utility data and the sellers’ own published prices, with every source listed.
Softeners
Water softeners, explainedHow a water softener works, the hardness level where one starts to make sense, what it fixes and doesn’t, the main types, and what they cost to buy and run.Salt-free vs. salt-basedHow salt-free conditioners and salt-based softeners differ, what independent scale tests found, what each costs, and where salt-based units are restricted.Softener sizing calculatorSize a water softener from your water’s hardness and your household’s water use: a calculator, the formula, and how to measure what you actually use.Water softener costWhat whole-house water softeners sell for, from online brands’ own stores and dealer brands’ published ranges, plus salt-free systems, filters and upkeep.Softener installation costWhat installing a water softener involves, which brands sell for do-it-yourself installs, what plumbers earn, and what dealer prices include.Dealer softener pricesWhat Culligan, Kinetico, RainSoft and EcoWater publish about softener prices, how each sells, their stated warranties, and how to compare a dealer’s quote.
Filters
Whole-house filter costWhat whole-house water filters sell for, from cartridge systems to carbon tanks and dealer installs, what they remove, and which appear in certification listings.Under-sink filters and ROHow under-sink carbon filters and reverse osmosis systems differ, what they sell for, and which models appear in NSF and WQA listings for PFOA and PFOS.Whole-house reverse osmosisHow whole-house reverse osmosis works, what it needs in space, power, drains and pre-treatment, how much water it sends down the drain, and store prices.Well water filtrationWhich treatment fixes each well water problem: iron, rotten-egg smell, hardness, bacteria, acidic water, nitrate and arsenic, with store prices for each.
Water quality
Hard water, explainedWhat water hardness measures, how to convert grains per gallon and mg/L, the USGS hardness scale, and the hardness level where a softener starts to pay off.EPA’s PFAS rule, explainedWhat EPA’s 2024 rule on PFAS, the “forever chemicals,” requires of water utilities, what EPA proposed to change in 2026, and how to read your city’s result.Chlorine vs. chloramineWhy utilities add chlorine or chloramine, how to tell which one your water has, and which filters remove each one.
Testing
Well water testingEPA’s checklist for testing a private well: the four things to test every year, when to test right away, and how to find a certified lab.How to test water hardnessFour ways to get your water’s hardness number, from free to lab-grade, how to read the result in grains per gallon or mg/L, and where to take the sample.
Research
Hard water and your healthEczema, hair, heart, kidney stones, sodium from softeners, appliances and petsPFAS and your healthWhat EPA, the National Academies and the WHO’s cancer agency found, and why the limit is 4 parts per trillionLithium in tap waterWhy EPA tests for it, how its screening level was set, and the mental-health studiesChlorine and chloramineWhat agencies say, and what happens with dialysis, fish tanks and skin complaints