AquaFirst water purification effervescent tablets (NaDCC, also known as sodium dichloroisocyanurate or sodium troclosene), is one form of chlorine used for disinfection. It is popularly used to treat water in emergencies but is now widely available for household water treatment as well.

AquaFirst tablets are available with chlorine content of 8.5 mg NaDCC, 5mg av cl, to treat from 1 litre of water at a time. They are effervescent (meaning that escaping carbon dioxide gas causes the tablets to dissolve quickly, with a 'fizz'), allowing the tablet to dissolve in less than 1 minute. When added to water, NaDCC releases hydrochloric acid which reacts through oxidization with microorganisms and kills them.

AquaFirst dosage is easily applied by following the clear and descriptive instructions printed on the carton (box).

• In general, add one tablet to one litre of water to be treated.
• Agitate the container for 5 minutes and wait out the amount of time instructed on the package, normally 30 minutes (also referred to as “contact time”).
• The water is then disinfected and ready to be used.