I have heavily highlighted, naturally curly hair. I have city water, but live in an old Victorian that has old plumbing. By using Malibu C Hard Water Wellness Shampoo 2-3 times a week, I am able to keep my hair a beautiful baby blonde. The best part of Malibu C products is they are gluten-free so my scalp and body do not break out in horrible rashes. I am always safe with Malibu C. :-)