White spots on glassware or silverware in the dishwasher is caused by the hardness or mineral content of the water. When deposits have built up, the opaque white particles are granular and can be crushed with your fingernail. The reason? The hardness of the water.

One of the most frequently asked questions we hear at Irvine Ranch Water District (IRWD) is, "Do we have hard water?" The one-word answer to that question is "yes," although the degree of hardness varies depending upon the time of year and your location within the District.

Water hardness refers to the mineral content in the water and is commonly expressed in "grains" of hardness. Generally water with 10 grains or more is considered "hard." Water imported from the Colorado River and Northern California averages 9 grains of hardness, while IRWD's well water averages only 8.3 grains of hardness.

While the hardness of the water does not affect its safety, the higher mineral content can typically cause white spots on glasses in the dishwasher or mineral build up on shower heads. Because IRWD uses mostly well water between April and October and mostly imported water the rest of the year, you may notice these things more during the winter. IRWD customers who live in higher elevation areas such as Foothill Ranch and Portola Hills receive mostly all imported water year-round and therefore have more consistently hard water.

For glassware issues, it is best to read the owner's manual for your dishwasher and follow the manufacturer's recommendations regarding settings for hard water. Some other tips that may help reduce spotting include using hotter water, varying the brand and type of rinse agent and detergent, and adding white vinegar to the rinse cycle of the dishwasher.

For build up on the shower heads, the deposits can be periodically removed by attaching a plastic bag with a small amount of vinegar in it to the shower head. Remember to use caution if small children can access the solution.

Water Quality Decision Tree