Over Dosing Of Dechlorinator

Something I came across. Here goes.

I got a response from Hagen about dechlorinator and if it is possible to overdose on it.

My email:

QUOTE
Hello.

I use Aqua-Plus water conditioner in my aquarium to remove chlorine,
chloramine and trace metals from my tap water.

I am also a member of a few different fish clubs, and a common debate
is whether it is detrimental to fish's health and water quality to add
too much water conditioner, or "overdose on dechlorinator" as it's
been stated.

I understand that your formula is patented and you won't tell me what
it's made from, but can you shed some light on this for us? Is the
dechlorinating chemical in your aqua-plus water conditioner natural or
synthetic? and is it possible to use too much? If I spilled an
entire 473ml bottle into a 50 gallon aquarium by accident, do I have
cause to worry? Hypothetically, that is.

Thanks for your time,
Matt



The response I received less than two hours later (I am impressed with Hagen's customer service response time)


QUOTE
Dear Matt,

Aqua-Plus has been tested in toxicity tests to 100 x overdose without
any problems for the fish, so as far as the accidental overdose scenario
is concerned, there is very little to worry about. When you are dealing
with a hard chemical such as chlorine, there is no known natural
substance grown that would do the job, so basically the active
ingredient to remove chlorine and chloramine is a standard chemical
which has been used for decades by aquarists. I have never heard of any
problems with it. That compound is sodium thiosulphate. There are
others, but this has been found to be the safest and still most reliable
way to eliminate chlorine immediately.

Now, with that said, as an old time pet store operator, there is a case
where a chlorine remover is detrimental to the environment. It is an
extremely isolated case, but since you ask, here goes. When the water
is treated with chloramine, the standard dose is at least twice as much
as for chlorine to break the chlorine-ammonia bond, release the ammonia
and neutralize the chlorine. This was exactly the case in Edmonton,
Alberta in the early 70's where the common strategy of using 4x dose was
historically suggested. This never caused a problem except in one
particular set of circumstances....when an aquarist simply replaces
evaporated water and uses an even more excessive dosage rate (about 10 x standard chlorine recommendation) and never removes and replaces water for a standard water change. In this case, besides the tremendous
problems the building wastes of the tank incur, the sodium thiosulphate
will precipitate in combination with chlorine to the bottom of the tank
and build up concentration. When it reaches a critical concentration,
since all it can do is stay in the tank, the reaction (sodium
thiosulphate reacts with chlorine and forms a precipitate) reverses and
can, under severely neglected conditions seem to release chlorine back
to the tanks. Just one more reason to encourage all aquarists to
properly maintain the tank with standard water replacement rather than
simply filling when evaporation is encountered.

Hope that helps in your arguments about safety. As I said, the above
case is very radical, tanks had to be neglected and overdosed on a very
regular basis for at least a couple of years, so in most cases the fish
will die of neglect and horrendous environment long before the chemical
reaction is allowed to reverse.

Best Regards,

Steve Pond
Rolf C. Hagen Inc.