Hi DJ,
Basically yes but:
Natrium sulfphate or Nat Sulphate is a very refined form of Sodium Thiosulphate use in Homeopathy for different things. Being very refined it is weaker than the sodium Thiosulphate we use in koi ponds to bind chlorine.
If you are going to use it for chlorine elimination best and cheapest to stick with Sodium Thiosulphate.
Chris