San Diego Hard Water, Explained

Where San Diego's water comes from

San Diego gets very little rain, so most of the region's water is imported. A large share comes from the Colorado River through the Colorado River Aqueduct, and more comes from Northern California through the State Water Project. Local reservoirs catch what rain we get, and the county also buys desalinated seawater from the Carlsbad plant.

Colorado River water picks up calcium and magnesium on its long trip across the desert, and those dissolved minerals are what make water "hard." Utility water quality reports for the San Diego area regularly list hardness above 200 milligrams per liter, which falls in the "very hard" range.

Hard water is safe to drink. It's a nuisance, not a health hazard.

What hard water does around the house

• Kettles and coffee makers: the minerals come out of the water as white scale when you heat it. It builds up inside kettles, clogs coffee makers and makes them run slower.
• Dishes and glass: spots on glasses and a cloudy film on shower doors.
• Soap and shampoo: hard water doesn't lather as well, so you tend to use more.
• Skin and hair: many people say their skin feels tight and their hair feels dull or stiff after showering in hard water.

Fix it for drinking, coffee and cooking: purified water

Reverse osmosis takes out most of the dissolved minerals that cause hardness. That's why coffee and tea made with purified water taste cleaner, and why kettles and coffee makers stay scale-free much longer.

A purified water refill at Fresh Alka Water is $0.70 a gallon, or $3.50 for a 5 gallon water bottle. Many people keep a gallon jug next to the coffee maker just for this. See purified water refills.

Help in the shower: a shower filter

A shower filter mainly reduces chlorine, and many customers tell us their skin and hair feel nicer after adding one. To be clear, a shower filter isn't a water softener. Softening a whole house takes a whole-house system.

We carry Rainshower dechlorinating shower filters and bath filters. See shower filters for San Diego hard water.

Quick tip: descale what you already have

Fill your kettle halfway with equal parts white vinegar and water, bring it to a boil, let it sit for an hour, then rinse well. For a coffee maker, run the same mix through a brew cycle, then run two cycles of plain water. Switching to purified water afterward keeps the scale from coming back.