Pretoria
Pretoria, South Africa has an estimated water hardness of 73 ppm (mg/L as calcium carbonate), which is classed as moderately hard. Some mineral build-up is possible in heated appliances.
Pretoria water hardness in every unit
| Unit | Reference estimate |
|---|---|
| mg/L or ppm (CaCO₃) | 73 |
| mmol/L | 0.73 |
| German degrees (°dH) | 4.09 |
| French degrees (°fH) | 7.3 |
| Clark degrees (°e) | 5.12 |
| Grains per US gallon (gpg) | 4.26 |
Published range: 49–97 ppm.
How the Pretoria figure was derived
- Period covered: 2024-07-23 – 2025-07-22
- Calculation: The source publishes a mean and a standard deviation. The average is that mean; the range is the mean plus or minus three standard deviations, not the observed minimum and maximum.
Where Pretoria's water comes from
- Supplier: City of Tshwane, supplied in bulk by Rand Water and Magalies Water
- Source: Bulk treated water from Rand Water, which also supplies Johannesburg, plus Magalies Water
- Official website: City of Tshwane
Rand Water’s 12-month report for its supply to Tshwane shows a mean hardness of 72.9 mg/L (standard deviation 8.0) against an operational range of 20 to 200 mg/L. Areas supplied by Magalies Water may differ. Rand Water: 12 Month Water Quality Report, supply to Tshwane (July 2025) (checked 2026-10-31).
How Pretoria compares
With a reference estimate of 73 ppm, Pretoria ranks 36th hardest of the 69 cities in our directory, close to the directory median of 74 ppm. Among the cities in our directory in Africa, Johannesburg is the hardest at 74 ppm and Cape Town is the softest at 34 ppm.
What the range means
Published figures for Pretoria run from 49 to 97 ppm. The spread is relatively narrow (48 ppm), so the average is a reasonable guide, though your own tap can still differ from the citywide figure.
What moderately hard water means at home
Moderately hard water can leave light white deposits on kettle elements, taps and glassware over time. It is usually manageable with periodic descaling, and many households need no softening equipment at all.
Using a 73 ppm reading with your appliances
- Dishwasher: salt check manual; match the converted reading to your model. Use salt only as specified for the built-in softener.
- Coffee machine: descale when the manual or machine indicates; filter: use only a compatible filter specified by the manufacturer.
- Laundry: use the medium-water dose. Follow the product label for your load size.
- Kettle: Inspect for scale; follow the manual.
- Humidifier: For ultrasonic or impeller units, use low-mineral water such as distilled water. Empty and dry portable tanks daily; clean every third day. Follow manufacturer instructions.
Official manufacturer guidance
Use these references with your exact appliance model. They explain settings and maintenance, not the local water measurement. Source languages and model limits are shown; these are not affiliate links.
- Bosch South Africa — Dishwasher quick-start guide (en-ZA)
Measuring hardness, adjusting the softener from the model’s table and using salt and rinse aid.
- Bosch South Africa — Cleaning your dishwasher (en-ZA)
Official dishwasher-cleaning guidance with related descaling support.
(checked 2026-10-20).
Hardness alone does not determine maintenance frequency. How to match your reading to an appliance manual. Dishwasher settings by brand: find your setting. Thinking about a softener? Pros and cons and sizing. Kettles and coffee machines: descaling guide. Portable humidifier care: US EPA guidance.
Frequently asked questions
Do I need dishwasher salt in Pretoria?
Check manual. Use salt only as specified for the built-in softener. Always follow your dishwasher manual.
How often should I descale a coffee machine in Pretoria?
Descale when the manual or machine indicates. Hardness alone does not determine an interval: usage and appliance design also matter. Water filter: use only a compatible filter specified by the manufacturer.
Do I need a water softener in Pretoria?
Usually not. Appliance settings and occasional descaling are normally enough, but a filter or softener is a personal choice if you dislike spotting.
Is hard water in Pretoria safe to drink?
Water hardness is mainly an aesthetic and scale issue. The World Health Organization does not set a health-based guideline value for it. Hardness affects taste, scale and detergent use rather than drinking safety, and your utility is responsible for meeting drinking-water standards. If you have a specific health or dietary concern, ask your doctor.
How to check your own water
City averages are a starting point. To get your actual figure, check the linked source (Rand Water: 12 Month Water Quality Report, supply to Tshwane (July 2025)) and obtain a current report for your address from your water supplier, or dip a hardness test strip in a glass of cold tap water and read it against the chart. Strips usually report in °dH, gpg or ppm; enter the number into the Waterdial checker to convert it and see the matching appliance settings. Use a recent, correctly performed hardness test when a city estimate is too broad.
Source
Rand Water: 12 Month Water Quality Report, supply to Tshwane (July 2025), checked 2026-10-31. Guidance is general; your appliance manual takes priority.
Learn more about water hardness on Wikipedia
Check a different location or enter your own reading →