by Melissa J Luther

Created on: April 14, 2007   Last Updated: December 25, 2008

Water hardness is a measure of the minerals, mainly magnesium and calcium, dissolved in the water. These minerals exist in water as cations (positively charged ions). Water picks up these cations from rocks and sediment as it travels within the earth. Water hardness varies by location, because different types of rock contain varying amounts of minerals.

>Permanent vs. Temporary Hard Water<

The cations in water are balanced by anions (negatively charged ions), and these anions determine whether the hardness is permanent or temporary. Water containing carbonate and bicarbonate anions is temporarily hard. Temporary hardness can be removed by boiling, which causes the carbonate ions react with the cations. This reaction forms insoluble carbonates that precipitate out, softening the water.

Permanently hard water typically contains chloride or sulfate anions, which do not react with the cations during boiling. Despite the name, permanent hard water can be softened, but it requires an ion exchange system.

>Hard Water: Advantages and Disadvantages<

*Advantages

On the positive side, hard water may actually be better for drinking. Not the very hard water with the metallic taste, but slightly or moderately hard water. The minerals in hard water are essential minerals, which means they are necessary for human health. The evidence is inconclusive, but some studies suggest that heart disease rates are lower in areas with hard water.

Hard water is also better for watering plants and grass.

*Disadvantages

Hard water causes that hard-to-remove scummy film on bathtubs and shower doors. This film occurs because cleaning agents do not fully dissolve in hard water, and the undissolved cleaners stick to any surface they touch. This residue is also the reason clothes washed in hard water feel stiff and hair becomes lifeless and dull.

The calcium and magnesium in hard water build up in pipes, washing machines, boilers and other appliances. This scaly build-up results in clogged pipes, reduced water flow and shorted appliance life-span.

>Soft Water: Advantages and Disadvantages<

*Advantages

Soft water is preferable for cleaning. Because cleaning agents dissolve better in soft water, there is no sticky residue left behind on tubs, clothes or hair.

Soft water does not result in scale build-up in pipes, washing machines and boilers. No build-up means better water pressure and longer appliance life.

*Disadvantages

Soft water may not be suitable for drinking. Softening treatments often

• 1
• 2
• Next Page >>