Thanks for raising this issue. I live in Tucson, Arizona, where the water is hard beyond belief, and I have hard water stains all over the place. No chemicals that I have found in various hardware or home-improvement stores work on this, and vinegar is hopeless. I have a professional window washer coming on Friday, and I am hoping he can clue me in to some magic formula. If so, I will tell all!

Limeaway or CLR, use with lots of patience. I've been able to knock the encrustation loose with a wooden stick after liberally applying either cleaner and letting it 'soak'. If the air is very dry, I've put a rag over everything to keep it wet. The wood won't scratch the way metal might.

If you are going to use CLR or Limeaway, but prefer to use less chemicals, you might as well be using vinegar. I have cleaned some thick, stubborn heavy buildup with the stuff in bathrooms and kitchens, including shower glass, coffee pot, dishwasher....The key is soaking it for a while and having some patience. Try soaking a cloth in vinegar and leaving it on your faucets for at least an hour. The toothbrush is an excellent tool for getting at hard to reach spots when it is time to scrub...it will not scratch surface.

We have awful hard water stains on our bath fixtures (especially showerheads) out here in Nevada too. NOTHING worked for me until I tried a very, very thick paste of lemon juice and baking soda. Mix it so it is a thick paste and apply it to your faucets with an old toothbrush. Let it sit for about an hour, then scrub and rinse. You might have to repeat a few times, but it does get them clean, and all-naturally at that. Hope this helps, and good luck!