Learn before you buy
Plain answers on how softeners and filters work, what size you need, what's in your water and how to change your own filters.
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Guides and Comparisons
Best shower filter for hard waterWhat a shower filter can and can't do for hard water, and how to pick one.Learn more
Best Water Softener SystemThe best water softener system for most homes is a whole-house system sized to your water: a softener for hardness, carbon for chlorine or chloramine, and reverse osmosis for drinking water. Ours, the City Water System, is $2,950 installed. Not sure it fits your home? A rep will call you and answer every question.Learn more
How does a water softener workA water softener removes the calcium and magnesium that make water hard by trading them for sodium or potassium. This is called ion exchange.Learn more
How hard is your waterHard water is common across most of the US. See how hard the water is in your state and city.Learn more
Salt vs salt-free water softenerSalt-based softeners remove hardness minerals. Salt-free conditioners change them so they don't stick as scale. Here's which fits your home.Learn more
Water softener brands comparedHow the major softener brands compare on price, installation and service, so you know what you're paying for.Learn moreWater softener vs water filterA softener removes hardness minerals. A filter removes things like chlorine, sediment and chemicals. Many homes need both.Learn more
What is reverse osmosis, and how does it workReverse osmosis pushes water through a membrane with pores so small that most dissolved solids, metals and chemicals get left behind. Here's how it works, step by step.Learn more
What size water softener do I needMultiply the people in your home by 75 gallons a day, then by your water hardness in grains per gallon. Pick a softener that covers about a week of that.Learn moreWater Problems, Solved
Arsenic in well waterArsenic occurs naturally in some groundwater, especially in private and small shared wells. Here's how to test for it and which filters reduce it.Learn moreHard water in the showerA shower filter reduces chlorine at the shower head, but only a whole-house softener removes hardness. Here's what each can do for your skin and hair.Learn more
Hot water smells like rotten eggsIf only your hot water smells, the cause is usually inside the water heater: the anode rod reacts with bacteria in the tank and makes the gas. When we install your softener or water system, our plumber checks your anode rod and swaps it if needed, so the smell doesn't follow you. [Confirm whether the swap is included or quoted.]Learn moreMicroplastics in your tap waterTiny plastic particles have been found in tap and bottled water. Here's how they get there and which filters are built to catch them.Learn moreMost filters don't remove fluoride. These do.Most standard filters don't remove fluoride. Reverse osmosis is one of the few home systems that can. Here's what works.Learn moreNitrates in your well waterNitrates come from fertilizer and septic systems and mostly show up in well water. Here's how to test and what removes them.Learn moreSulfur water filterA sulfur filter removes hydrogen sulfide before it reaches your taps. We test your water first, so the filter matches how strong the smell is.Learn moreWater Smells Like Rotten EggsThat smell is usually hydrogen sulfide, a gas most common in well water. Here's how to find where it's coming from and get rid of it for good.Learn moreWorried about lead in your waterLead usually gets into water from old pipes and fixtures, not the treatment plant. Here's how to check and which filters are certified to reduce it.Learn moreYour city uses chloramine. Here's what filters it outMany cities now use chloramine instead of chlorine, and it's harder to filter out. Here's which filters handle it.Learn moreHow to Change Your Filters
Change Whole-House FilterHere's how to change a whole-house filter safely, and when it's better to book a plumber.Learn moreHow to Change RO FiltersRO pre-filters and remineralization cartridges usually need changing every 6 to 12 months. Here's how to do it.Learn moreHow to change your water filters, step by stepStep-by-step guides and videos for every filter we sell, plus how often to change each one.Learn moreReplace Shower CartridgeSwapping a shower filter cartridge takes a few minutes and no tools. Here's how.Learn moreWant the Answer for Your Home?
Tell us your ZIP code and a rep calls you within 5 minutes to answer every question. No pressure, no sales visit.