My understanding of the use of Sodium thiosulphate is that it will only
break the chlorine/ammonia bond thus neutralising the chlorine but leave
behind the ammonia. If the ammonia level is high then it can kill your fish.
I guess in well established aquarium the biological filtration may in some
cases handle the extra ammonia but in new or somewhat overcrowded tanks,
this could be a problem. It probably also depends on what quantity of
chloramine your local water board uses. If you don't want to use a
Chloramine remover then to be on the safe side you should test you ammonia
levels after using the Sod thiosulphate.
Adrian.
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Adrian R. Tappin
"Home of the Rainbowfish"
http://www.ecn.net.au/~atappin/home.htm
http://www.angfa.org/rainbowfish/home.htm
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