I have these recurring nightmares about needing to
rescue koi that are dying in truly strange ways.

The other morning my nightmares sort of intersected
reality.

When I stocked my koi pond, I put in about six
koi, because I did not want it overstocked in
case something went wrong. I figure with 1500
gallons, they would be fine. Problem is they
spawned roughly 30 babies and I have not had the
heart to take the babies out yet, and they
are getting bigger each year.

The pond is split into an upper and lower part
with a waterfall in between. I also comitted
a general no-no which is to have a pretty high
plant load in the pond as well. The upper
pond works as a vegetable filter, and the
water stays very clear, but the plants, of
course, consume oxygen at night.

Over the course of the winter, my pump's water
volume decreased by probably a factor of five.
It happened so slowly that I really did not
realize how bad it had gotten. I would take
it out and clear stuff that had visibly gotten
past the skimmer and lodged in the pump. But
I did not realize that hard little seed-like things
were getting lodged in the slots that drive the
water up into the outtake, and I could not see
them there. So I would look at the pump, see that
it was clean, and never really clue into the fact
that somehow it did not have the water flow it
used to have.

I think the decreased trickle allowed the oxygen
volume to drop in the lower pond, because that
pond is fundamentally overstocked and the upper
one is only available as an oxygen reservior if
the pump is working well enough.

I don't know exactly *why* but I started having issues
with the pump blowing the ground fault detector.
I have zero idea why that happened, but one night
it must have blown just after I went to bed.

I woke up to find all the fish, of course, gasing
at the surface. Most of them were distressed but
still mobile and reactive. The largest one was,
well, almost dead. Its eyes were glassy and it
was unresponsive when touched. It did finally
swim away but only to end up on its side with
its head partly in the skimmer.

I had to go to work. I got the pump started,
hoped the daylight would help oxygenate the
pond and somewhat unhopefully hoped for the best.

I left work early to go home, fully expecting the
big guy to be dead, and at least partly expecting
many or all to be dead. But when I got back, the
big guy had recovered and was swimming along happily.

I ripped out a bunch of plants. Added some large
reserve oxygenation with an air pump, discovered the
blockage in my main water pump, and then decided
to wait to remove the extra stock. I *REALLY* need
to make myself do that. I am hoping I can donate
the babies to my local Bottanic Gardens.

Anyhow, do you guys run plants in your koi ponds?
Many people say koi will destroy them, but that is
just BS. I have lots of plants that coexist with
my koi, but I am beginning to question the wisdom
of keeping them.

doug