Sodium Thiosulphate

Sodium Thiosulphate can be used to remove chlorine from water and is quite often used in Photographic processing. It has also been used in the medical industry as a treatment for Cyanide poisoning.

It can be used as a dechlorination agent for swimming pools and aquariums. Sodium Thiosulphate reacts with the chlorine in chlorinated water/tap water neutralising it, making the water safe. Standard tap water usually has a chlorine content of around 3-4 ppm chlorine, this level can be toxic to pond or aquarium fish, so treatment of tap water is always essentail before replacing pond or aquarium water. For dechlorination of 10 litres of standard tap water at 4ppm chlorine content, between 0.1g and 0.2g of Sodium Thiosulphate is required.

Sodium Thiosulphate is also used by photographers as a photographic fixer. It has a high affinity to soft metals and a solution can be used to dissolve photographic emulsions.