Hard water causes limescale deposits, which create white spots, streaks, and cloudiness on glasses. Most people don’t even realize they live in a hard water area. If you are unsure but do have white spots on your glasses, do the vinegar test.
Luckily, there are things you can do to help with hard water issues. Use Finish® Jet Dry® and Finish® Power Up™. And Finish® All-in-1 Powerball® tabs in hard water areas above 120 ppm. Finish® Quantum® provides great performance in water up to 300 ppm.
For exact hardness check with your local water company.