FritzPro Sodium Thiosulfate

  • Concentrated, dry powder
  • Instant neutralization of chlorine and chloramines in municipal tap water
  • Eliminates harmful heavy metals
  • Safe for use in fresh and saltwater

About FritzPro Sodium Thiosulfate

Fritz ProAquatics Sodium Thiosulfate Pentahydrate can be used for the neutralization of chlorine (including chloramines) and/or iodine in water. Chlorine is toxic to fish and invertebrates so whenever chlorine is used, for example disinfecting tanks or equipment with sodium hypochlorite (bleach) or using tap water during transport or stocking, it is crucial to remove chlorine prior to the introduction of fish or other aquatic life.

Directions & Dosage

To make a sodium thiosulfate solution for dechlorination of tap water: Mix 500 g Fritz Sodium Thiosulfate in 1 gallon of purified RO/DI water. The resulting solution should be dosed at 4 mL per 10 U.S. gallons to remove up to 4 ppm chlorine. Test for free chlorine after dosing, and repeat 4 mL per 10 U.S. gallons as necessary until chlorine levels reach zero. 

USAGE NOTES: For the neutralization of Chlorine: – The amount of sodium thiosulfate required can vary with the pH of the water. A range of approximately 2 to 3 parts sodium thiosulfate to neutralize one part chlorine is typically suggested. The use of a chlorine test kit is recommended to determine final chlorine concentrations.


Size Treats Item Number
1 lb / 453 g when prepared: 9460 gal / 35,810 L 97641



See below for frequently asked questions regarding FritzPro Sodium Thiosulfate.

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