Reduce limescale and preserve the environment. If you live in a hard water area and struggle with limescale, the use of a water filter tap reduces - and in some cases removes - limescale in and around your kitchen tap. Limescale is caused when tap water evaporates, leaving calcium carbonate behind. Water filter taps not only remove a majority of calcium carbonate from water, but other harmful toxins and chemicals ensuring you have the freshest water available. More importantly, buying bottled water is not only expensive long term, but is also incredibly harmful to the environment.