aesthetic
Water Hardness (Calcium/Magnesium) in your water
Is Water Hardness (Calcium/Magnesium) in drinking water dangerous?
It depends on the level and how long you're exposed. The EPA has set no federal legal limit for Water Hardness (Calcium/Magnesium). Meeting the legal limit isn't the same as zero risk — test your water to know your level.
How do you remove Water Hardness (Calcium/Magnesium) from water?
Water Hardness (Calcium/Magnesium) is treated by Water Softener and Reverse Osmosis. Choose a system independently certified to NSF/ANSI standards to reduce Water Hardness (Calcium/Magnesium), and test your water first to confirm the level.
Source: EPA MCL / MCLG; WHO guidelines; NSF/ANSI · 2026
Health effects
Hardness is dissolved calcium and magnesium. Not a health hazard, but it causes limescale on fixtures and water heaters, spotting on dishes, reduced soap lather, and can shorten appliance lifespan. Measured in grains per gallon (gpg).
The health-based goal vs. the legal limit
The federal legal limit (MCL) is the maximum allowed by law. The EPA health goal (MCLG) is the level below which no health risk is expected — it is non-enforceable and often stricter than the legal limit.
EPA health goal (MCLG)
No federal health goal set
Federal legal limit (MCL)
No federal limit set
Source: EPA National Primary Drinking Water Regulations (MCL / MCLG) · 2026
What removes Water Hardness (Calcium/Magnesium)
Ion exchange
Water Softener
Swaps the calcium and magnesium that cause hard water for sodium — so scale stops forming.
Look for: NSF/ANSI 44 certification
How it works→Semipermeable membrane filtration
Reverse Osmosis
Pushes water through a fine membrane that removes the dissolved solids most filters miss.
Look for: NSF/ANSI 58 certification
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Is Water Hardness (Calcium/Magnesium) in your water?
Check your city's public record, then book a free 30-minute test to confirm what's in your home.