WaterCriteriahttps://watercriteria.comWater filter and treatment guides: reverse osmosis, whole-house and under-sink filters, softeners, well-water systems and testing, compared by certification, capacity and cost to own.en-us How to Choose a Whole-House Water Filterhttps://watercriteria.com/guides/how-to-choose-a-whole-house-water-filterhttps://watercriteria.com/guides/how-to-choose-a-whole-house-water-filterChoose a whole-house water filter: match media to the problem, size the flow rate, read micron ratings and plan for iron, sulfur and UV on well water.Fri, 06 Nov 2026 00:00:00 GMT Pitcher vs Under-Sink Water Filter: Cost, Capacity and Performancehttps://watercriteria.com/guides/pitcher-vs-under-sink-water-filterhttps://watercriteria.com/guides/pitcher-vs-under-sink-water-filterPitcher, faucet and under-sink water filters compared on certified reductions, capacity, flow and cost per gallon, with simple running-cost math.Fri, 06 Nov 2026 00:00:00 GMT Reverse Osmosis vs Carbon Filter: Which Problem Does Each Solve?https://watercriteria.com/guides/reverse-osmosis-vs-carbon-filterhttps://watercriteria.com/guides/reverse-osmosis-vs-carbon-filterReverse osmosis vs activated carbon filters: what each removes, wastewater, minerals, installation and running costs, matched to your water test.Fri, 06 Nov 2026 00:00:00 GMT Water Filter Certifications Explained: NSF/ANSI 42, 53, 58 and 401https://watercriteria.com/guides/water-filter-certifications-nsf-standardshttps://watercriteria.com/guides/water-filter-certifications-nsf-standardsWhat NSF/ANSI 42, 53, 58, 401, 55 and 44 certify, how to read a certification listing, and why a filter's box claims are not the same as certified claims.Fri, 06 Nov 2026 00:00:00 GMT Water Softener Sizing: How Many Grains Do You Need?https://watercriteria.com/guides/water-softener-sizing-guidehttps://watercriteria.com/guides/water-softener-sizing-guideHow to size a water softener: convert hardness to grains per gallon, estimate daily use, allow for iron, and pick a capacity that regenerates weekly.Fri, 06 Nov 2026 00:00:00 GMT Well Water Testing: What to Test For and How Oftenhttps://watercriteria.com/guides/well-water-testing-guidehttps://watercriteria.com/guides/well-water-testing-guidePrivate well testing guide: annual bacteria and nitrate tests, when to test for arsenic, lead and more, how to sample, and how to pick a certified lab.Fri, 06 Nov 2026 00:00:00 GMT