What Is the Difference Between Calcium Hardness and Total Hardness

What is “calcium hardness” and “total hardness” and what’s the difference between them? Calcium hardness is the measurement of dissolved calcium in hot tub or pool water. Total hardness, which is measured by different test kits, measures both the calcium and magnesium present in water.

What is the difference between hardness and total hardness?

Hardness makes a water hard to soap, caused by the presence of bicarbonates, carbonates, chlorides and sulphates of Calcium and Magnesium, all dissolved in water. TDS is total dissolved solids, that conduct electricity and expressed in parts per million (milligrams in 1 litre water or mg/kg).

Is TDS the same as calcium hardness?

TDS and hardness are water quality parameters. The main difference between TDS and hardness is that TDS include inorganic and organic substances that cannot be filtered through a filter paper whereas hardness is due to the presence of magnesium and calcium salts of carbonate, sulfate and chloride.

Maya Lin-Takahashi

Maya Lin-Takahashi

Consumer Tech & Gadget Reviewer

Maya is a hardware enthusiast who tests and reviews smart home devices, smartphones, wearables, and audio gear. She focuses on practical consumer value and build quality.

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