By Emma Mackenzie While not actively harmful to your health, limescale is an incredibly common and unsightly scourge on many households, particularly those who live in hard water areas, where the mineral deposit builds up more easily. Technically, limescale is mostly made of calcium carbonate, and even if it isn’t harmful to drink, it can impact the efficiency of your appliances, which can be frustrating. The chalky-looking deposit can stop them from working as well, meaning that they can cost more to run, or eventually need to be replaced sooner than you might have expected, making it potenti…