Koi Pond: Fish or No Fish?

If a pond has a waterfall to aerate the water, fish willand nearly self-sufficient. As long as you only stock
produce waste that is broken down by nitrifyingthe koi pond with small fish such as guppies and
bacteria into nitrate nitrogen, and water plants will usemosquito fish, they will never need to be fed. They can
the nitrogen and thrive. In turn, the fish eat the algaeexist solely on food that the pond provides naturally. A
and small water insects that live on the rocks and plantchlorinated pond, on the other hand, requires continuous
roots. And those bugs eat other smaller bugs that eatmaintenance. The chlorine dissipates from the water
microscopic bugs that eat bad bacteria bugs. This isas it flows over the falls and turns into chlorine gas.
called the nitrogen cycle. A properly balanced pond likeThis means that fresh chlorine needs to be added
this will pretty much take care of itself... What is a koiregularly and your backyard will smell like a swimming
pond without koi? A pond! Now that is boring...pool all the time. The chlorine also causes many
Many clients who want a waterfall and koi pond dominerals and suspended particles to precipitate and
not want koi fish to take care of. Actually, a pond willbuild up on the rocks, causing unsightly white stains in
require less attention with fish than without. If a koithe water's path. When chlorine is not added regularly,
pond has a waterfall to aerate the water, koi fish willleaves and other decaying debris in the pond will
produce waste that is broken down by nitrifyingcause algae to grow, turning the pond green. So after
bacteria into nitrate nitrogen, and water plants will useconvincing the client to give my suggestion a try, I
the nitrogen and thrive. In turn, the koi fish eat the algaereturned a few weeks later to find that they have not
and small water insects that live on the rocks and plantonly purchased some large koi fish, but have given
roots. And those bugs eat other smaller bugs that eatthem all cute names, like Charlie and Doug.
microscopic bugs that eat bad bacteria bugs. This isIf the client wishes to have larger fish such as koi, the
called the nitrogen cycle. A properly balanced koi pondnitrogen cycle will need a little extra help from a
like this will pretty much take care of itself.biological filter and an ultraviolet light. The larger the
Koi fish food can get lodged in the plants, rocks andnumber and size of the koi fish, the greater the waste
vegetation around the perimeter of the koi pond. If thematerial produced. This means that some of it must be
koi fish cannot find the food, it simply decays, addingremoved from the water. Increased quantities of
unnecessary nitrates to the water and resulting innitrates and nitrites increase the amount of ammonia
more food for algae to grow. To eliminate this problemand other by-products such as pea soup algae, the
I fashioned what I term as a Koi Fish Food Corraltype that turns the water green. A biological filter will
made from a 4 to 5 foot piece of 1-1/2 inch flexibleaid in the breakdown of toxic nitrites into less harmful
PVC pipe and fastened together with a single 1-1/2nitrates, and an ultraviolet light will kill algae spores and
inch coupling, creating a circular corral.disease-causing pathogens as they pass through the
This corral keeps the koi food in one place, andUV light on the way to the filter. So, what else can I
prevents it from floating off into rock crevices, plantssay to convince you to get fish? They are fun to
or the skimmer. Plus it allows for the proper portioningwatch? They are cute? They come in handy during
of koi food. It is easy to tell if you've given the koi fishtimes of famine? Got fish? Got turtles? Got tadpoles?
too much. If food is still there after a couple of minutesNo? Then, get some! Your pond will be much more
and the koi fish seem to have had enough, they have,appealing and exciting. It is like having the Learning
and you should remove the leftovers. Lay it in the sunChannel or Discovery Channel in your back yard.
to dry and feed it to them later. It is easy to collect theEvery day brings a new discovery: baby fish hatching;
extra food that the koi fish don't eat by using a smalla dragonfly struggling from its cocoon; a tadpole
net. It is better to feed them too little than too much. Inslowly, very slowly, turning into a frog; two crayfish,
a case like this, more is not better.doing what they do to make baby crayfish... now that
Sometimes my clients originally expressed a concernis a discovery! A turtle, shedding its shell... now that is a
that koi fish would be a burden or a hassle. Theymiracle. If you have kids or grandkids, or neighbor kids,
would worry about having to feed them daily, or whatgrab some or all of them and make it an adventure.
they would do when going on vacation. I would explainPile them into the car or bus and go to the local pond
that the koi fish are extremely important with regard tostore and gather up a passel of predacious and
their contribution to the nitrogen cycle. The nitrogenpeculiar pond creatures. Better yet -- build a koi pond
cycle is what makes a koi pond low in maintenancefirst and then do it. Happy koi, peace and joy.