Water Hardness Guides
Data-driven research to help you understand your water quality and make informed decisions. Every guide is backed by real water hardness data from 31,000+ US locations.
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Water Hardness Scale: PPM and GPG Chart
Use the USGS water hardness scale to compare PPM, GPG, and mg/L levels from soft to very hard water.
Hard Water vs Soft Water: Key Differences
Compare hard water and soft water by minerals, taste, soap lather, skin, hair, plumbing, and treatment needs.
How to Test Water Hardness at Home
Compare free lookups, soap tests, test strips, liquid drop kits, and lab tests for measuring water hardness.
Water Hardness Scale: PPM and GPG Chart
Use the USGS water hardness scale to compare PPM, GPG, and mg/L levels from soft to very hard water.
10 min readHow to Test Water Hardness at Home
Compare free lookups, soap tests, test strips, liquid drop kits, and lab tests for measuring water hardness.
8 min readHard Water vs Soft Water: Key Differences
Compare hard water and soft water by minerals, taste, soap lather, skin, hair, plumbing, and treatment needs.
10 min readDo You Need a Water Softener? (Based on Your Water Hardness)
A data-driven guide to help you decide if a water softener is worth the investment based on your actual water hardness level.
10 min readHard Water and Hair: Effects, Damage Signs & What Actually Helps
How mineral buildup affects your hair - and what to do about it based on your actual water hardness level.
10 min readHard Water and Skin: Effects on Eczema, Dryness & What Helps
How hard water minerals affect your skin, why eczema flares in hard water areas, and what actually works to protect sensitive skin.
9 min readTDS vs Water Hardness: What's the Difference?
TDS and water hardness measure different things. Learn why a TDS meter can't tell you if your water is hard, and which test you actually need.
7 min readWell Water Hardness: Why It's Usually Hard & How to Treat It
Well water is almost always harder than city water. Learn why, how to test your well, and the best treatment options for hard well water.
8 min readPPM to GPG Converter + Water Hardness Scale Explained
Convert between PPM and GPG instantly. Understand the USGS water hardness scale and what your numbers mean for your home.
5 min readHardest Well Water Cities in America: The Complete Ranking
The top 50 US cities with the hardest well water, ranked by verified USGS groundwater data. See where the hardest water belt runs and why geology matters.
10 min readWater Hardness in California: From Sierra Snowmelt to SoCal Scale
California has a 130x range in water hardness - from 3 PPM in the Sierras to 400+ in Ventura County. Verified with State Water Board lab data.
12 min readMichigan Water Hardness: How GLWA Treatment Creates an 8x Difference
Detroit metro gets treated Lake Huron water at ~100 PPM. Drive 90 minutes to central MI and well water hits 700+ PPM. Here's why.
10 min read