Due to geographical conditions, most municipal water supplies and private well water in North America—including Canada (excluding the Maritime provinces)—are hard water. Hard water is perfectly fine for outdoor uses such as watering gardens, washing parking spaces, and sprinkling lawns. However, for indoor uses—such as showering, shaving, washing dishes, furniture, and clothes, as well as for appliances that use large amounts of water, such as air conditioners, humidifiers, and washing machines—soft water offers better benefits and results than hard water.

The drawbacks of hard water include the need for more detergent or soap when washing; soap scum left on bathroom tiles, which can harbor bacteria and be difficult to clean; stains remaining on cups, plates, and porcelain ware after washing; limescale reducing the efficiency of home water heaters, leading to significantly higher gas and electricity bills; shortening the lifespan of appliances; and soap scum and limescale residue on the skin and hair, which can cause inflammation and sensitivity issues.

The primary minerals responsible for water hardness are calcium carbonate and magnesium carbonate. When these substances dissolve in water, they cause the water to become hard. According to Water Quality Association standards, water is considered hard if its hardness exceeds 1 degree (1 GPG).

Water Hardness Standards:
– Soft water – Less than 1 GPG
– Slightly hard water – 1–3.5 GPG
– Moderately hard water – 3.5–7 GPG
– Hard water – 7–10.5 GPG
– Very hard water – Over 10.5 GPG

Water hardness in Ontario ranges from 1 to 120 GPG: North Bay – 1 GPG (soft water), Toronto – 7.5 GPG (hard water), Waterloo – 28 GPG, and Kitchener – 40 GPG (very hard water)

Hard water can be treated in two ways to produce soft water. One method involves adding chemicals to detergents, soaps, or water to counteract the negative effects of hard water. The preferred method is to use a water softener, which employs a physical process of cation exchange to remove and flush out the minerals responsible for water hardness.

By Michael Chiu, MWS, CI
Previously published in Ming Pao Daily News