Hard water spots on your shower doors makes it look like it isn’t clean. Try Rain-X Original Glass Treatment, a car-care product made to keep rainwater off your windshield and use it twice a year. Or, if you would like a home remedy try rubbing a teaspoon of lemon oil on the glass shower doors twice a month. It will cause water to bead up and roll off just like the bought product and it smells great! For other ideas, check out our cleaning tips to beat hard water build up.