Your mission is to remove these hard-water spots and lime deposits on the shower walls and glass doors. Sodium carbonate is the base for many cleaners and is the main ingredient in washing soda. It's what you're looking for. It'll dissolve crusty white lime deposits and hard water spots. If it doesn't work, try a squirt or two of liquid toilet bowl cleaner. Wear rubber gloves, protect your eyes and avoid fumes. And that's the On The House tip for today.