What is water hardness?
Water hardness is defined by the level of dissolved calcium Carbonate (CaCO3) that water contains measured in milligrams per litre.
| Water Hardness Classification | ||
|---|---|---|
| Classification | Milligrams per Litre (mg/L) | Comments |
| Soft | 0 – 60 | Salty taste; Some report that soft water may aggravate cardiovascular diseases,
but this hasn’t been backed up by WHO. |
| Moderately hard | 61 – 120 | Good for drinking |
| Hard | 121 – 180 | Good for drinking |
| Very hard | 181+ | Unpleasant taste; slightly bitter |
Water hardness by Australian city
Analysis of water hardness in major Australian cities by the Australian Water Association shows a range from very soft (Melbourne) to hard (Adelaide).
| Capital City | Water Hardness | Capital City | Water Hardness |
|---|---|---|---|
| Melbourne | 10–26 | Adelaide | 134–148 |
| Canberra | 40 | Brisbane | 100 |
| Sydney | 39.4–60.1 | Hobart | 5.8–34.4 |
| Perth | 29–226 | Darwin | 31 |
While larger cities tend to get water supplies from surface waters and therefore have softer water, more isolated cities and towns are more likely to experience hard water because they are supplied primarily by groundwater sources. Calcium and magnesium which cause water hardness are natural minerals which dissolve as water moves through soil and rock. They cannot be removed by filtration, but water in the moderately hard to hard range is regarded as perfectly safe and healthy to drink. It is a bit of a pest though when it comes to scale left on things like water filters, kettles, taps, pipes and drains, and trying to get a lather up when using soap.
Tap with built-up calcification from hard water. Picture by Bbypnda [1]
The effects on industry
In households this scaling and poor lathering may be more of an inconvenience than anything else but when it comes to industry it can be a major problem. Calcification can and does lead to a reduced energy efficiency and an increase in failures of equipment like boilers used for heating. It also leads to an increase in the corrosion of galvanised metals, and an increased use of soap due to the difficulty in forming a lather. Dealing with hard water has been described as one of the largest causes of wasted energy in the world. For these reasons a number of companies including EZEK offer water softening solutions like ion-exchange resin devices, lime softening systems, chelating agents (chemicals), distilling and reverse osmosis systems.
EZEK’s TAC water softener series uses an advanced catalytic lime softening technology to convert hard water minerals into harmless, inactive sub-micron crystals.
In the first stage, calcium and magnesium ions join to the carbonate ions form a crystalline nucleus.
The second stage: The crystals of calcium carbonate and magnesium grow to sub-micron size and release into the water, effectively softening it.
Call us today on (02) 8840 5177, or email us at sales@ilanwater.com.au, to discuss our range of water filtration systems to provide clean and great tasting drinking water at your home or office.
Australia-wide delivery available!
Effects on human health
There is a long held belief in some scientific circles that hard water, particularly water with higher magnesium levels, may have a cardiovascular benefit. However, this is a subject of some conjecture with the World Health Organisation stating the data was inconclusive and more study is required. Dr Frantisek Kozísek, head of the National Reference Centre for Drinking Water in Prague, Czech Republic suggests that levels of calcium and magnesium in drinking at 40–80 mg/L and 20–30 mg/L, respectively could be beneficial to human health and found no evidence it would do any harm. [2]
Hard water then is unlikely to hurt us and may even be healthy and beneficial to the human body, but can be an annoying and expensive problem for household and industrial plumbing and appliances. For the industrial plumbing and appliances though, extra measures will have to be taken to counteract the reduction in energy efficiency and equipment failures.