Page 81 - Koi Net - On-Line Koi Magazine - Issue 92

If we were to extrapolate this to our Koi ponds, the
percentage of nitrogen that is removed in the pond
through bacterial growth could be quite large. If you
clean your filter, wash away the crumbled sludge
underneath your filter mats, you lose the nitrogen
bound to the cell wall / bacterial material in this way.
However, we use food that contains more protein, so a
higher percentage is likely to be converted to nitrate in
our ponds by autotrophic bacteria. After this article,
it is likely that what remains of Ammonia/nitrogen
compounds after the autotrophs have done their work,
so to speak, is largely eaten by the heterotrophs and
thus leaves our ponds via sediment. However, if in our
Koi ponds the carbon source (including sugar but
especially dirt or sludge accumulation is a source of
carbon for them) is finished, then the heterotrophs can
no longer do all that much. So be careful when adding
packages of yogurt and other sweet nutrients that are
not intended for Koi at all. It sounds like a treat for your
Koi, but you add sugars so you can now get more
unwanted bacterial growth. Ebeling describes in this
article that you can actually use the heterotrophs as a
filter, so in theory you don’t need any other filter
bacteria. However, this is with a very special test
design, and in our Koi ponds that is a utopia and a
good disaster recipe. Never consciously go that way,
you will not succeed without misery with your Koi. As
mentioned earlier, too much heterotrophic growth is not
favourable because these make the bacterial pressure
in the water too high, which in turn causes our Koi to
suffer a lot of misery. We can therefore better ensure
that less Carbon and Ammonia also remains for the
heterotrophs, or does this already happen automatically?
In any case, another process will have to take place to
get rid of the rest of the nitrate.

In my next Article I will explain more scientific studies
and their results and implications for keeping Koi.
Topics will be to have a detailed look at biofilms, and
the gills of carp where also bacteria reside.

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