the  recorded  health  improvements.  (If  koi  have
been  very  seriously  metals  damaged,  they  may
not all recover.)     Minor   improvements   have   included   such
things as better colours and cessation of flicking
after  water  changes.  Moderate  improvements
have  ranged  from  healing  of  fins  and  small
lesions  to   koi  no  longer  needing  spring  and
autumn  treatments  for  parasites  because  they
developed  sufficient  strength  (fighting  fit!)  to
ward off parasitic invasion themselves.     Major improvements have been dramatic. One
koi  keeper  had  such  high  bacterial  levels  in  his
pond  that  a  monthly  bactericide  treatment  was
necessary. This was apart from having replaced
and  up-graded  the   biological  filters,  having
bacteria  identified  and  koi  injected  with  the
appropriate  antibiotic.  He  was  down  to  four
surviving  koi,  some  were  still  ulcerated.  The
correct purifier was installed after the water had
been tested for metals, iron was found to be one
of  the  main  problems.  One  year  later  with  no
further    antibiotics,    bactericides    or    other medications  the  koi  were
fitter,  healthier,  ulcers  had
self-healed  and  pond  water
bacteria levels had dropped
to acceptable amounts. The
only intervention                                       was
lowering   the   metals   and
raising the alkalinity levels.
Four   years   on   from   the
horrors,  the  first  new  fish
have   been   added   to   the
pond.     How  did  we  turn  round
our  disastrous  pond  mark
four  to  a  pond  fit  for  koi?
Again, the                                      only
intervention we took was to
lower the substances in the
influent tap                                   water,
particularly the metals.     If   you   decide   to   have
water tested for metals you
need to follow a few simple
rules.     When   looking   to   find
released   metals   from   an
object  then  it  is  important
that  three  different  water
samples  are  collected  and
tested  individually.  These
should   be   collected   from
water immediately before it
enters   the   object,   from
water leaving the object and
also  from  the  pond.  Each
sample should be tested for The Kohaku was damaged by ‘metals’, it developed ulcers. It was correctly treated, metals were ‘removed’ from pond water. The Koi healed and is alive and well today. Photographs courtesy of John Towler