Because I have very hard water, I clarify every couple of weeks. Back in the south I rarely had to clarify because the water was soft. When I moved out here, I developed breakage galore, and my hair had become stiff and always dry. When I realized my issues were caused by hard water, I bought a bottle of Suave clarifying shampoo and it was like night and day. My hair was finally back to normal. Through research, I've found that any clarifying shampoo I use has to have the EDTA ingredient in it to remove mineral deposits.