Chlorine in water reacts with living tissues and organic matter causing cell
death (acute necrosis) in fish. Since fish gills are sensitive and exposed
directly to the aquatic environment, the death of cells in the gills - the
fish's breathing apparatus - can lead to respiratory difficulty and
asphyxiation.


"David Larson" wrote in message
...
Hello all,

My local water board informs me that the water out of my tap has 4 ppm of
chlorine. I know this is
way too high, and it will be treated accordingly to make it safe.

My question is this - what exactly does chlorine do to koi? Yes, I know it
kills them... but I want
to know what takes place inside the fish, chemically, that causes them to
die?

- David