Please refer to your owners manual for instructions on using citric acid for descaling.
Cleaning Kettle - Add 50grams of citric acid to kettle and enough water to cover all the limescale. Leave for an hour then dump liquid down the drain and rinse the kettle
Cleaning Glass Shower Door - Put citric acid in a small bowl and add water to make a paste. Apply the paste to your glass shower door. Leave for at least 5 minutes. Wipe clean with a sponge to take off limescale.

citric acid

450 grams of citric acid in a 500ml clear glass jar with black metal lid.

Citric acid is a natural and biodegradable substance that is found in citrus fruits. It is often used for descaling coffee machines, kettles, shower doors and the inside of washing machines and dishwashers.
The base of bath bombs is 2 parts baking soda to 1 part citric acid.