Hard Water and Your Plumbing

What hard water is

Hard water carries dissolved calcium and magnesium. They do no harm to drink, but they leave scale when water is heated or evaporates.

Find out your hardness

Ask your water provider for its hardness numbers, or use a test kit. Homes on cisterns or private systems may have very different water from the city's.

Effects on the home

Scale narrows pipes, clogs aerators and showerheads, shortens the life of hot water tanks and appliances, and leaves spots on dishes and glass.

Simple fixes

Soak aerators and showerheads in vinegar to dissolve scale. Flush the hot water tank once or twice a year.

Softeners

A water softener removes hardness minerals for the whole house. It needs salt and occasional service. See water softeners and filters.

Choosing a system

Size matters: too small and it can't keep up; too big and it regenerates less efficiently. A plumber can size one from your hardness and household water use.

Tankless heaters and scale

Tankless water heaters are especially sensitive to scale, because water passes through narrow passages that heat very quickly. If you're thinking of going tankless and your water is hard, ask whether the manufacturer recommends a softener or a regular descaling routine.

Signs in the hot water tank

A tank that pops or rumbles when heating is often carrying a layer of scale on the bottom. That layer makes the burner or element work harder and can shorten the tank's life. Flushing helps on a younger tank; an older one may be better replaced.

More plumbing guides

• Chinook Freeze-Thaw and Your Pipes
• Finding Your Main Water Shut-Off
• Reading Your Hot Water Tank Label
• Backwater Valve Basics for Lethbridge Basements
• Hiring a Plumber in Alberta