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A water-hardness order should specify what is being measured and how the result is expressed. Total hardness, calcium hardness and a standard expressed as CaCO3 are not labels to use without checking the method.
Online Reagents is backed by PMA’s chemical-manufacturing experience of more than 52 years. Send your specification online to discuss suitable supply, availability and quantity before confirming an order.
Identify the hardness measurement
Water hardness commonly relates to calcium and magnesium. The USGS hardness explanation provides background on this relationship. An instrument method may measure total hardness or a particular component.
Specify the result required by your site’s procedure. Do not assume that a calcium-only method will supply a total-hardness result.
Record the complete reporting units
Many hardness results are expressed as an equivalent concentration of calcium carbonate, written as CaCO3. This reporting basis should be copied exactly, alongside the units and range. It does not mean that every standard must be interpreted as a bottle of suspended calcium carbonate.
Avoid comparing results with different reporting bases without an approved conversion. Send the existing specification if the required basis is unclear.
Distinguish reagents from standards
A reagent participates in the test; a standard provides a stated reference under specified conditions. One does not automatically replace the other. Our hardness reagents and standards page provides a route to discuss both requirements.
Match the analyser’s titration method
Identify the instrument, titrant specification, indicator and any other required components. The sequence and range are method-specific. Hach’s hardness methods overview illustrates why selecting by parameter name alone is insufficient.
Confirm package format and connection requirements, and follow the approved procedure when changing reagents.
Make ordering details easy to check
Supply the make and model, total or component hardness requirement, reporting units, range, existing reagent references, bottle sizes and quantity. Describe separately any verification standard required.
Hardness should also not be confused with alkalinity. If both parameters are monitored, make two distinct specifications; our alkalinity reagents guide covers that separate requirement.
Will one hardness standard suit every method?
Do not assume universal suitability. The stated concentration, composition, documentation and intended procedure need to match the application. Confirm those details before ordering a replacement standard.
Ready to discuss water hardness reagents and standards? Share the analyser details and required specification so our team can help check the next step.
Explore water hardness reagents and standards
Need help with water hardness reagents and standards?
Contact our team about this article or your reagent requirement. Include the analyser make and model, method, range and quantity so we can respond to the right specification.
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