"Dr Engelbert Buxbaum" wrote in message
...
Fallout wrote:

Hi

I have been trying to source a supply of dechlorinator that does nothing
but
dechlorinate. According to my LFS the Tetra product only contains Sodium
thiosulphate, but the label says that it will also remove heavy metals.

I am not sure how soluble iron thiosulphate is, but thiosulphate is used
only in tiny amounts (it catalyses the chemical conversion of
hypochloric acid) and is rather unstable, so it won't last long in a
tank. For both reasons I would not expect it to have a major effect on
iron concentration.

If nasa can't remove heavy metals from their water I don't think a fish
tank chem can. It's a pretty lame claim as the tiny percentage these
products can remove is hardly going to impact anything but THE most delicate
marine organism ever for better or worse.
Just my take
If you want pure sodium thiosulphate why wouldn't you just get it from a
photography developement store?