Seasonal Koi &
Pond Care... |
Living
in a cold climate has some draw backs concerning Koi keeping.
Ideally these lovely fish should be raised in a place where seasonal
temperature's typically vary from 10°C to 30°C
- while they may be cold blooded they are not
cold water fish.
One of the most important factors to koi making it through our
long winters is water temperature - below 7-8°C over
too long a period and the koi are "surviving". Koi do
not hibernate - they are not mammals. Koi are cold blooded
or poikilothermic, meaning their body temperature/metabolism
is regulated by their surroundings - WATER - as they have no mechanism
in which to do so themselves. It's also important to note that
their immune system is regulated this way as well - the cooler
the water the lower the immune system, making koi vulnerable regarding
health issues. Koi and goldfish can suffer from "hypothermia"
so it is important to try the best you can to keep the ponds water
temperature above 4-5°C.
Unless a pond is indoors here in Canada, those "ideal"
temperatures just aren't possible all year round. Here in our
part of Ontario summer air temperatures can reach well above 30°C
with humidity while winter air temperatures can plummet far below
-10°C. There are a few different
ways to winterize an outdoor pond in which fish reside, dependent
on the design, to insure things run smoothly in the following
spring. Even with careful planning,.. sometimes there may be fish
losses come spring. Our winters can be very cold and very long,
sometimes to long...
Over
the past years our methods for wintering koi have changed somewhat.
Each winter presented it's own dilemma's which we had to adapt
to in keeping our koi "alive". 2003/2004 none of our
koi spent the winter outside.... we had moved and there was no
pond. The koi were wintered in our heated garage in a wood/liner
tank that Ian made. I'm not sure we will ever subject our
fish friends again to Ontario's winter elements....
Below
you find what "was" - meaning
what we experienced and how we managed to get our koi through
the cold months in past years.
For
a couple years we over wintered a few koi in less than 1000gal pond.
The pond was 3' deep. At first we tried using a small water pump(250gph)
set about 6-8" deep to keep a hole open... this method was
short lived. I woke one morning in late December to find the pond
completely iced over. It took several pots of boiling water to thaw
out a hole. That same day I purchased a "pond deicer",
similar to a cattle trough heater(1500w !). We
placed the deicer on a timer to come on for a few hours during the
coldest parts of the day and night. This kept a large surface area
free of ice and maintained the water temperature at around 5°C.
The koi seemed ok, all huddled together at the bottom, occasionally
on warmer days we observed them munching on algae.
Hoping so save some money on electricity we purchased a lower watt
deicer in 2001. This worked well at keeping a small hole open but
the water was much colder. We had tried covering the pond with a
plastic shelter but found that the water temperature fluctuated
far to much from day to night for our liking and seemed to cause
added stress to the koi. In retrospect the volume and depth of the
pond were contributing factors to our observations.
This was before the pond upgrade in 2002...
 |
Dec
2002 the pond froze over so fast the ice was as clear as glass
with a depth of 24inches. |
Our
Method:
Going
into the fall we constantly monitor the pond water's temperature.
When it starts sitting in the 16-18°C range we introduce
a wheat germ based food, weaning of the higher protein diet, and
cut back on the feeding schedule. Water changes of 10-20%
are done weekly with filter maintenance At this time we transfer
any 3-6" Koi indoors to over-winter in a DIY quarantine
tank.
By
the time there is a drop in water temperature to 13-10°C
the Koi are on a strict Wheat gem diet and feeding is limited
to once or twice daily in small amounts. We also observe them
grazing more readily on algae. Once again we continue our filter
maintenance and partial water change routine.
The
3500gph pump is replaced with a smaller 1500gph pump when 7-8°C
water temp is reached, with the return placed 6-8"
below the water's surface. The bottom drain diffuser is also shut
down. The filter is given a good cleaning and a portion of the
bio media is brought indoors, added to our indoor tanks filter.
When
water temperatures are on a steady decline, surface water
ranging 4-5°C , the 1500gph pump
is removed. A final filter cleaning is done along with a small
water change. A 100w deicer is then put in place. Now the waiting
for spring thaw....
|
Dec
2001 |
Nov
2002 |
From
our past experience in allowing the majority of the surface to ice
over, the water temperature remained stable through out the winter
season. Ice cover helped protect the waters surface from wind chill
and lessened evaporation. We found that the average water temperature
remained at 4°C during the course of the winter months.
Depending on the depth of the pond, there may be a layering
effect - surface being coldest, middle being average, and bottom
sitting at the warmest. This can only happen if there is little
or no circulation of the water. It is important to keep
a hole in the surface for gas exchange.
Added Winter Cover...2002/03
We
were noticing a decline in the ponds pH and KH... The 100w deicer
has not been able to keep a large enough hole open so gas exchange
had become an issue along with all the snow cover and the ice being
so thick we believed the algae was dying off from lack of light
- all this leading to the KH issue... So off to get some supplies
and construct a temporary cover for the pond to see if it would
help. The hope was that the cover would help retain some heat which
should melt some of the ice to let more surface water open up to
keep the water parameters more stable and possibly warm the water
up a degree or two. The deicer was still in use and a small bubbler/air
pump was added. One week later and there was a noticable improvement.
The ice had started to retreat and become thinner, we did add baking
soda(as a buffer) to up the KH. Outside temperature's had been dipping
below 0°C
but inside the structure seemed warmer and pond temperature
held around the 4-5°C
mark.
|
Plant
pond was cleaned and pots dropped, no fish
in here. This water garden at the deepest point is 24". Ice
thickness in these pictures is roughly 12" and it's early December
2002. By January 2003 the pond was pretty much frozen solid. The
gas bubbles sure make for an interesting argument that ponds with
fish need an open hole for off gassing.
|
Below
is a rather nice article on wintering ponds and koi, it's a good
read.
Stay tuned
for additions regarding spring start-up and summer care.
|
Preparing
for winter - a 2004/05 approach
Posted at NI by
J.P. Reilly on 9/29/2004
It is getting close to
the end of active koi keeping season for many of us now. And preparations
should begin in the next few weeks.
If you are in the east coast region of the USA from DC up to upstate
New York ( this also holds true for England I’m sure) you
will notice that your koi’s appetite is beginning to change.
Because your koi is truly part of its environment, changes are happening
IN the koi and AROUND the koi at this very moment.
Your koi’s biological clock, triggered by night time water
temperature, air surface temperatures and light changes, now is
telling the koi what is about to happen- winter! This clock is also
telling the females that spring breeding isn’t so far off
and preparations must be made for that event as well. Therefore
you koi will get hungrier! You will notice that they will eat more
aggressively. Part of this is due to higher oxygen levels and better
OPR readings this time of year which results in better water quality
in general and part is the considerable influence of that biological
clock.
You must now decide what you will be going with your fish come Dec.
1? Will they be under a protective tent or inside? Will they be
left under ice to take their chances or will they be given only
the illusion of winter ( mild heat and covered)? Only love, depth
of concern, monetary value and economics will determine this answer.
In the ideal, your pond should already be netted ( berry netting
available at any garden center or Home depot) to keep falling leaves,
twigs and airborne materials from settling into the pond. The koi
should be moved to a wheatgerm and fresh food diet about now and
away from the high protein pellets. The number of meals and amounts
can also begin to come down. I feed the same number of times this
time of year ( three or four) but I reduce the amounts and already
have opened my first bag of wheatgerm pellets. As water cools and
the sumps are less burdened by organics, you will notice your koi’s
white skin get much whiter.
Once Nov. Rolls around, your tent should be completely installed
and ready to go as the cooler nights of late November will bring
the water temps down considerably. During this time, you can usually
depend on solar effects during the day and you can close the tenet
at night to retain some heat. Remember, the tent acts as a heat
space that separates your ponds water surface from the cooler air.
My heaters usually start going on and off during the week of Thanksgiving.
Once you water hits 50 F stop feeding. If you must, for emotional
reasons, feed the koi- feed very small amounts and fresh food is
better than pellets.
Now you are in the ‘ winter zone’. This can be real
or man made. The difference being -a conscience decision to:
A) flirt with the carp population’s known
survival ranges or
B) to limit the ‘ winter zone’ to individual
koi’s optimal temperature range.
This is simply saying that at the most basic and primitive koi keeping
level, temperatures near or below 0 C ( 32 F ) will test the survival
abilities of each koi- young/old, well conditioned/ poorly conditioned.
And nature tells us that a large percentage will make it through
the challenge with only minor health issues the following spring.
This older technique is pretty much passe in modern koi keeping
but some water garden hybrid koi keeper types still practice it
to this very day. And even this group is divided into those that
let ice form and those that keep the ice off and keep things running.
Both have their gamble. One allows gas to build and if a koi dies,
that death can stress, sicken or kill the other fish. The no ice
crowd will keep koi swimming in cold water and if the winter is
long, the koi run out of gas and stress, sicken or die. This also
allows winter precipitation to influence water parameters and water
quality. And allows water to actually drop below freezing at some
point- negating the passive warming effects of the earth. So IMHO
the pond MUST be tented .
The second, more evolved approach B ( heat and tent) is to only
allow temperatures to fall low enough to give the effects of the
‘ winter zone’ without testing survivability of each
individual fish. This gives the desired effect in regards to the
fish’s metabolic needs and seasonal shift but not an exhaustion
or associated stress of a full blown winter survival challenge.
This low end range then would be 45- 55 F/ 8-13 C.
The next decision that will separate ‘survival’ from
‘optimal’ will be the length of the ‘ winter zone’.
The winters in the North East are long! As they are in England.
In the primitive technique of koi keeping, a young koi may be asked
to hang on for as long as 16 weeks. This is a lot to ask of the
better breed koi from Japan. So parasites in spring, the illusion
of a thing called aeromonas alley and general infection are all
very real possibilities. The koi is simply weak and exhausted. An
easy target for a pond that is becoming biologically active in an
organically rich warming environment.
In the second technique, a man made artificial ‘ winter zone’,
the winter cycle can be easily controlled. ‘winter’
can be as short as 6- 8 weeks and never dip below 45F. But be aware,
low light conditions will still keep koi inactive and experiencing
the seasonal influences.
* Regardless of which
path you take, the pond should be kept clean and netted as the winter
zone approaches. And normal maintenance should continue, albeit
reduced somewhat. Water changes should continue, only smaller and
less often. Sumps should be dumped, only less often.
* Equipment should also be checked as we all tend to not want to
go out there! I also recommend a spare pump in reserve for that
Sunday morning disaster!
* Drain all ‘ summer lines’ that can freeze. Make Thanksgiving
weekend your drop dead date! If your are going to go ‘ primitive’
you need to consider freezing of lines- even if you keep the water
running. This is why two speed pumps make some sense on one level
and not much sense on another. Same is true with the use of ball
values. Reduced flow with create a chance for ice to form and actually
crack a schedule 80 ball value!
* stop all feeding once you reach your chosen ‘ winter zone’
. Another last minute meal is meaningless and can actually do more
harm than good.
* the berry netting will keep ‘most’ leaves out but
some how some will make it in so before adding the tent, make sure
the bottom is clean.
* Look into buying a heater. This is the ultimate control over winter
and the associated problems of the old way of keeping koi at the
most primitive level.
I
would like to thank JR for giving permission to post his thoughts
here on Backyard Puddle. ~Terri |
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