The water we use at home is often described as ‘hard’ or ‘soft’. These labels describe the way water behaves when soap is added to it.

Here is what we usually observe when a soap solution is added one drop at a time to hard water. Make a note of everything that you see.

Compare this with what happens when we add the soap solution to soft water, and then decide how hard the water is in your home.

Two types of water hardness

Hard water contains dissolved solids. Watch what happens in the following animation: