Page 47 - Koi Net - On-Line Koi Magazine - Issue 70

ammonia added, it can be reduced by partial water
changes of, say, 50%.

It started well but suddenly went completely wrong
Biofilter bugs don’t just need ammonia or nitrite plus
oxygen and a source of carbon such as sodium
bicarbonate in order to grow and thrive. In common with
all other bacteria, they need other nutrients especially a
source of phosphorous or phosphate. If any of their
required nutrients that initially may be present in the
water should become exhausted then the maturation
process will stop dead. The bacteria that have grown up
to that point won’t die, (at least not in the short term),
but the ammonia level and/or the nitrite level won’t
reduce because the bugs simply cannot function
without all the nutrients they need.
If the process has stopped because the bugs have
used all the available phosphorous, a small dose of
tomato fertiliser will provide all the phosphate that they
need but that may not be the only reason so there is a
far easier solution. In view of the fact that the volume
of water is small, the simplest way to deal with any
situation where fishless cycling suddenly grinds to a
halt or where strange things seem to be happening with
the levels is to just drain the water and refill!
When the process is complete, all the water used in the
biological bay (container or dustbin) must be dumped
and the media lightly rinsed in dechlorinated water or
pond water to remove any residual ammonia or nitrite.
Once this is done the media will be ready for immediate
use and should be returned to the filter system and the
pond stocked as soon as is practical before the newly
grown bacterial colonies begin to die back through lack
of their nutrient supply.

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