as any koi keeper would expect but they were not a
major problem. Materials had been chosen very
carefully for the pond construction. We were told
our fish were strong and healthy and everything
would settle-down- but they just kept dying. And
no-one we contacted in the koi world was able to
help us in our Sherlock Holmes hunt to find the
underlying cause of the damage and deaths suffered
by our koi. As all older sisters, I have frequently
been heard telling my baby brother that he was a
total pain. He had never kept fish but in this
instance I, teeth-grittingly, have to admit that he
knew far more about influent water than me.
And I was, supposedly, an experienced fish
keeper. (It was useful to have a Principal Safety
Officer in the family who was in charge of well-
water testing for our local population!) Baby bro
arranged for us to receive a drinking water report to
find out what was in our tap water. Drinking Water
Report? In a span of 32 years of keeping fish Id
never heard that mentioned before. He also
arranged for our outside tap to be tested for
bacterial and faecal contamination - that bunch of
test results came back clear.
The drinking water report was a different story.
The report on our tap water showed that it was
excellent quality for drinking. We didnt, and still
dont, treat our tap water for our own consumption.
But as I keep saying so boringly, tap water is
designed for people it is not designed for fish.
Tap Water
The water report showed us the
fundamental and underlying cause of the
health problems for our own koi.
Amounts of Metals Extracted from Home Water Report
Aluminium
4 mg/l
Copper
50 mg/l
Iron
5-107 mg/l
Lead
4 mg/l
Manganese
10 mg/l
Zinc
126 mg/l
Measurement mg/l = ppb (parts per billion)
Unsuitable water butt lined with inert material so it could
be used safely as a tempory trickle tower filter
Although we hear a lot about aluminium
damaging koi it was only present at 4 mg/l. All of
these metals were well within the prescribed total
values allowed to be in peoples drinking water,
some were minuscule. Some metals were below the
safe level for fish some were well above the fish-
safe levels. Until we had this information our
attempts at treating our koi mainly failed. In
hindsight we understood why. Unless you know and
eradicate the underlying causes of fish health
problems all you do is treat the symptoms. Until the
underlying cause is known and solved, the koi
continue to face the same inherent problem - it
doesnt just go away. Thus, if you only treat the
symptoms, your intervention is likely at the worst