.] >> hi, i'm anne-marie howard, and if you're like me, you hate squeegee-ing the shower glass and mirrors... wiping spots off of dishes after they come out of the dishwasher... polishing bathroom hardware... or wiping slimy shower water off your body with a stiff, abrasive bath towel. all of these problems are caused by one culprit: hard water. well, today on 21st century green, i've invited my friend, home improvement and do-it-yourself expert jan muller to share something new. >> hi, jan. >> thanks, anne-marie. it's go to see you. >> you too. >> you know, hard water and the damage that it does is a real problem. as a matter of fact, over 80% of the homes in the country have hard water, and they all see the effects, just like you do. >> but, jan, i know hard water does more damage than what we just see. >> that's true, and that's why we're going to use this relatively new home to show everyone the damage done in just seven years by using hard water. as a matter of fact, the present owner selling the house is going to have to do major remodeling and start replacing faucets and fixtures, m