Sodium Thiosulphate Crystals 99% min

Water dechlorination for fish tanks, aquariums, aquaria, terrerria. 

Sodium thiosulfate is used predominantly in dyeing. It converts some dyes to their soluble colorless "leuco" forms. It is also used to bleach "wool, cotton, silk, soaps, glues, clay, sand, bauxite, edible oils/fats, and gelatin.

In photography, sodium thiosulfate is also known as a fixer and 'hypo', from the original chemical name, hyposulphite of soda. It functions to dissolve silver halides e.g. AgBr components of photographic emulsions. It is used for both film and photographic paper processing.  The ability of thiosulfate to dissolve silver ions is related to its ability to dissolve gold ions.