Imagine water are a bit like household wizards, able to use their spells to exculpate calcium and magnesium (the cause of scale and scum) from hard water. They are boxes which are about the size of a small desktop computer, and can be installed where the water supply enters the premises. They getto the heart of the problem, head on. It’s all done through a process called ion exchange, which uses resin. Imagine tiny polymeric beads,specially formulated so that they can be charged with certain ions. Calcium and magnesium, the causes of scale and scum from hard water, are referred to as ions, and as water passes through the resin, the calcium and magnesium ions swap places with the sodium ions on the resin. Sodium salts, unlike calcium and magnesium, are highly soluble so sodium does not cause scale or scum. When all the sodium ions have been exchanged for calcium or magnesium, the resin must be regenerated by recharging it with sodium ions. This is done by flushing the resin with salt solution (brine). So there you have it – a super scientific breakdown of exactly how water softeners grapple with unwanted elements and bacteria in your family’s water supply.