From The Aquarium Wiki
(Redirected from Sodium thiosulphate)
Sodium thiosulfate or Sodium thiosulphate (UK spelling) (Na2S2O3) is a chemical often used in commercial water conditioners to remove chlorine from tap water.
- When used on chloramine in tap water, it removes the chlorine and leaves the ammonia behind. So you need to find a way to remove this more dangerous chemical.