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  Holme’s  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  I’d
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 didn’t, and still
don’t, 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 mg/l Copper 50 mg/l Iron 5-107 mg/l Lead 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
doesn’t  just  go  away.  Thus,  if  you  only  treat  the
symptoms, your intervention is likely at the worst