White Vinegar or lemon juice should work, but you should address the real problem, the hard water. What ever you do don't just go out an buy a water softener from one of those big chain stores. However, You can could pick up a Do-It-Yourself water test kit there and then give me the results, and I'd guide you in the right direction. After you have your water test results and have some recommendations from me, you an go shopping. By go shopping, I mean look in you yellow pages under "water softeners" or "water Conditoning" or "water Treatment". Call all of them and have them come out to test your water, but don't tell them you already have test results or that you are getting quotes from other companies until after they have give you the test results and given you their sales pitch. This way you can week out the liars, and choose an honest company. I have been installing water conditioning equipment for 12 years, and hate to see people that have been taken for an expensive ride. I mean, some companies send guys out that will sell you the wrong equipment and charge a fortune to treat your water, these are only salesmen, they are not water experts. An informed customer, can easily weed out the bad guys from the good ones. Good luck and if you need any questions answered about water quality, e-mail me at jrfries@echoes.net