Water hardness is also a critical factor in food processing.

Cardiovascular disease has often been linked to water hardness as the main cause.

Other studies have shown weak correlations between cardiovascular health and water hardness.

Calcium chloride is used to increase the water hardness in swimming pools.

Water hardness means that there is magnesium in the water with calcium playing a role.

The researchers correlated the incidence of heart attack with the level of water hardness in their communities.

The sequestrant mechanism is also used to combat the effect of water hardness salts.

Individual test kits from Waterlife (£5.09) cover water hardness.

The ground water in Hyderabad has total water hardness up to 1000 ppm.

Lime addition increases the calcium ion concentration, thus raising the water hardness.

In the studies with the freshwater organisms, the water hardness for five of the six laboratories ranged between 36 and 75 mg/L.

This difference is caused by water hardness.

These are used in conjunction with water to maintain a consistent water hardness and level of metal ions.

It contains a number of impurities the sum of which are known as water hardness salts.

Water condition: Indifferent to water hardness; it requires neutral to alkaline conditions.

It's important to understand the effect that water hardness can have on your fish, especially when keeping sensitive soft water species, such as Discus.

Lively and peaceful, it does not thrive in high water hardness and needs to be kept in groups.

Limitation of this undesirable reaction is possible by controlling water hardness, detergent load and temperature.

The study found that the degree of water hardness as measured by mineral presence correlated directly with a lowered risk of heart attacks.

Otherwise, water hardness is measured in the metric unit parts per million (ppm), equivalent to mg/L.

Water's pH is closely-linked to water hardness.

Although a fairly wide tolerance level is exhibited by most freshwater fish it is better to adjust water hardness levels to suit the species.

Water hardness is classified based on the amounts of removable calcium carbonate salt it contains per gallon.

Water condition: Very indifferent to water hardness, but prefers a slightly acid to neutral condition.

Wherever water hardness is a concern, water softening is commonly used to reduce hard water's adverse effects.