Citric acid (250g)
Citric acid is used to descale limescale around the home. The white deposits that build up on kettle elements are perhaps the most recognisable signs of limescale. They can also be found on taps, showerheads and even in toilet bowls and the grout between tiles. There are also limescale deposits that can't be seen - such as in coffee machines, washing machines, steam irons and the heating elements of sterilisers for babies’ bottles.
To protect your appliances, descale them regularly to prevent build-up. The harder your water, the more regularly this will need to be done.
For kettles, simply pour some citric acid into the kettle - about a tablespoon full and add about an inch worth of water, so that the element or base plate is covered with water. Switch on the kettle and as it heats up, you will see the limescale fizzing as it reacts with the acid. You can turn the kettle off before it reaches the boil. If the fizzing stops and there is limescale remaining, then repeat the process until all limescale is removed. Usually it will be gone 1st attempt. Discard the water, rinse out the kettle a couple of times.