When people look into clean drinking water systems, particularly those that use reverse osmosis or water softening salts, they can sometimes be confused by the difference between hard water and soft water, which can lead to differences in taste, nutritional value, and limescale build-up.

Water hardness is a difference in what the water contains as it makes its journey to and from a water source such as a reservoir. As it travels along and through the ground, it picks up trace amounts of minerals such as calcium and magnesium before it makes it to your tap.

Water with a lot of calcium and magnesium is known as hard water, whilst water that travels through pipes and on impervious ground that does not pick up additional minerals is known as soft water.

Most of the time you cannot see the difference between hard and soft water, there are no adverse health effects drinking one or the other and it can take a discerning palate to even notice the difference by taste, but there are some noticeable differences that can matter sometimes.

The most annoying of these is that hard water can lead to limescale build-up which is an off-white deposit caused when the calcium is deposited on the side of pipes, in your kettle and on the ends of taps and showers.

If this builds up enough it can cause blockages and reduced water flow, which has led to some people using softening solutions to keep the water a certain softness, as soft water does not have this issue.

As well as this, soap can sometimes produce soap scum instead of lather, and the presence of calcium and magnesium does make hard water slightly healthier than soft water on the whole, although not to any significant degree.

In practice, whilst some people may prefer one taste to another, both hard and soft water, as long as they are clean and filtered, are as good for you as each other.