Are you a water gardener or a koi keeper? A little
of both perhaps? While many pond keepers have both koi and plants in
their ponds, koi generally require more specialized conditions to
thrive. Please note here that there is a distinct difference between
the words survive and thrive. Koi can “survive” in many environments
and may, for the most part, be happy and healthy. However, for koi
to “thrive” and have an attempt at reaching their genetic potential
as it relates to size, conformation, color, skin quality, longevity,
etc. they need special conditions. The purpose of this article is to
point out some of the major differences between a typical water
garden and that of a pond designed to keep koi.
Koi ponds should be at least 3’ deep over much of the pond
area. Four feet deep or deeper is preferred. Koi can grow to be
big fish. They need room to swim not only across a pond but up
and down as well. Some say that depth is important to help work
the fish and contributes to better conformation. Deeper water
also tends to keep a more stable temperature.
Koi ponds should have very steep, almost vertical sides, not
a gradual slope. This plays into #1 above. With steep sides, the
pond will hold more water and can be deeper with the same
surface “footprint”. Steep sides also discourage predators such
as raccoons and herons.
Little to no rockwork should be present in the koi pond. Too
many rocks in the pond can trap debris and injure koi,
especially during spawning. This item is sure to spark
controversy as some water gardens are totally lined with rocks.
Many koi keepers feel very strongly that a koi pond (a pond
designed to keep koi) should have absolutely NO rockwork what so
ever in the water. They feel the risk of injury to the fish and
the potential to harbor anaerobic bacteria far outweighs any
ascetic value.
Koi need substantial filtration unless dramatically
under-stocked. Typical requirements include: solids removal
(both large and fine), biological and ultra violet. Some will
take it a step or two further and utilize a foam fractionator
and a degassing chamber.
Koi need heavier currents in the pond and higher water
turnover through the filters. This helps exercise the koi and
provide for proper waste removal. Heavy aeration is also
required.
A bottom drain with koi is an almost necessity. Koi produce a
large amount of waste. It is important to remove this waste from
the pond as efficiently as possible.
Many koi keepers today are heating their ponds. This allows
the fish to thrive and substantially reduces disease and
parasite outbreaks in the spring. A heater also provides the
opportunity for an extended growing season in Ohio. Heating a
pond is a fairly expensive proposition, both from an initial
investment as well as an ongoing cost. There are however, some
huge benefits for the serious koi keeper.
Salt. From time to time it becomes desirable to add salt to
the water for the benefit of the koi. Many plants will not
tolerate salt at all. Other plants such as lilies and iris can
handle fairly high levels of salt for short periods of time.
The above list is by no means meant to be an absolute mandate in
successfully keeping koi. It does point out however the pond
conditions that have been proven over the years to develop award
winning koi. Can koi live and even be happy in an environment that
doesn’t meet the above requirements? Sure they can. But we’re
talking serious koi keeping here, right? If you want to truly
maximize the potential of your fish, try building your pond with the
above list in mind. Past experience tells us that you and your fish
won’t be disappointed.