To obtain an effective cleansing of your shower head and recover its shine, you just have to unscrew it and put it in a bowl with 1 litre of water, 100ml of liquid Citric Acid and a spoon of NortemBio Bicarbonate of Soda. Let it work for an hour.Then screw it back on place, open the hot water and let it run for 5-10 minutes.