Water conditions are the most important aspect of Koi keeping and should be mastered before introducing expensive Koi or too many Koi.
If your water conditions are not good, your Koi will not grow as fast, they will get sick regularly or they will die.
In short, the waste from the fish creates Ammonia which is deadly to the fish.
However, nature provided a nitrification cycle to solve this problem. Bacteria called Nitrosomonas grow in your Bio filter and pond and breaks down the ammonia into Nitrites. Nitrites are also deadly to fish, but Nitrites are being broken down by another bacterium called Nitrobacter into Nitrates which is beneficial to fish and plant life (but should also not exceed 50ppm).
The major reason for Koi deaths is overcrowding. A pond should NEVER have more than 10cm of Koi per 150 liters of water. I recommend at least 200 liters of water for every 10 cm of Koi.
Everything must be in balance like with everything in life.
To little Nitrosomonas causes too much ammonia, To little Nitrobacter causes too much Nitrites. The amount of fish, water volume and size of your biofilter MUST be in balance.
The biggest problem, a new pond and new biofilter needs time to create these bacterium. (at least two months) Introduce to many fish before the pond and filter becomes mature, will cause an imbalance. A pond takes up to one year to mature properly. Medicate the pond with certain medication without bypassing your bio filter will also cause an imbalance because the medication like Potassium Permanganate will also kill the Nitrosomonas and Nitrobacter. Cleaning your Biofilter to often or with normal tap water with chlorine contents, will also cause a problem.
Another problem, these two very important bacterium does not really grow in the winter. When the water temperature heats up in summer, the fish eat more, produces more ammonia, but the beneficial bacterium has not grown yet to sort out the Ammonia and Nitrites. This explains that most major outbreak of infections and poisoning in ponds happens in spring.
Hobbyists also tend to clean their ponds less frequently during winter. Leaves, sludge and other debris builds up, creating "bad" bacteria. As soon as the temperature increases, outbreaks follow.
Therefore, it is a good idea to ensure that your salt contents (which will kills most harmful bacteria/parasites) at the beginning of summer remains at least 0.3% and limit food intake during the first month of spring.
The chemical balance should be tested on a weekly basis, and every time any changes in the pond takes place.
At the beginning of summer, more regular testing should be done.
Therefore, a proper pond test kit is a must and is available at most Pet Shops.
Minimum allowed :
|
Ammonia |
less than 0.1 ppm(depending on temperature) |
|
Nitrites |
less than 0.2 ppm |
|
Nitrates |
less than 50 ppm |
|
pH |
6.7 -8.5 |
|
Alkalinity |
60 - 170 ppm |
|
Hardness |
75 - 150 ppm |
|
Chlorine |
less than .04 ppm |
|
Oxygen |
more than 5 ppm |
GREEN WATER Green water is not bad for Koi, as a matter of fact, it is very good for them
and breeders often prefer to keep their water green, because the fish thrive on
algae and ensure a good skin quality to the koi and enhance the colours.
However, we want to see our fish. Isn’t that what Koi keeping is all about? Very often, the quality of green water is much better than crystal clear
water. The reason why the water turns green is because of the accumulation of
nutrients in the water, especially those gathered during winter. The plants does
not grow actively in the winter and does not require a lot of nutrients. The
algae blossoms on these nutrients, and one must get rid of the nutrients and the
algae being the cause and the result. The other reason for green water (which is linked to the above) is because of
the absence of enough bacteria, especially directly after winter, because the
bacteria takes a while to grow after the winter months, as it requires enough
heat to grow. New ponds always go threw a phase of green water, despite the
presence of a UV light. This is nature's way of sorting out a balance. Don't
interfere unnecessarily. There are various options to solve the problem which can and should be used
in conjunction with each other, depending on the severity of the problem. Mechanical way An affective UV light will clear most of the floating algae which makes your
water green. However, it is very effective against blanket weed, the hardy type
of algae on the sides and bottom, but these does not affect the color of the
water and can be removed manually if required. One have to remember that the
tube is only really effective for a period of one year. So, if you have green
water despite the presence of a UV light, a replacement of the tube or an
additional light might be an option. It takes a few days to clear the water.
When you buy a UV light, always buy a bit bigger than what u actually require.
There is not a big difference in the price of a 15-watt and 30-watt UV light.
The one is approximately R 550.00 and the other one is R 620.00. We install 30
watt UV lights in ponds of 12 000 liters, although the manufactures indicate
that they are good enough for 30 000 liters. Chemical way There are various chemicals available on the market, the most common one is
"Pond Clear" which is available at most Koi outlets. It is fairly inexpensive at
approximately R 75 a jar, which is good for a few treatments on an average pond.
This will however cure the situation only temporarily, and it is extremely
important to use the right dosages, as it might affect your plants and fish
negatively. Some people use Potassium Permanganate, but it is not advisable for the
novice. If you suspect the presence of parasites anyway, this is an option. The
Potassium will attack the algae which will make your whole pond brown as it
kills the algae within hours, and leave a clean pond a few days later after a
water change. However, it also kills beneficial bacteria, unless you can
successfully bypass your bio filter. We do not suggest this option. Plants Another option is to introduce water plants or more plants that will use all
the nutrients and compete with the algae, and the algae will gradually die off.
Very often, Koi keepers introduce plants that were planted in nutrient rich
soil. This will initially cause the opposite and make your problem worst because
it normally causes an algae bloom. Water plants should be planted in normal
garden soil with low nutrients mixed with gravel, or only gravel, as apposed to
compost or rich potting soil. Bacteria Most types of bacteria breaks down the nutrients. Introducing a bigger bio
filter will cure the pond of algae, but it might take a few months. An option to
get the water clear much faster, is to introduce a bale of straw into the water
which will generate the right type of bacteria to limit the nutrients in the
water. This is why a mature pond normally have crystal clear water, and it is
difficult to maintain clear water in a newly build pond younger than 12 months. Shade To introduce more shade onto the pond, will also help to clear the green
water and it will help to prevent it from happening again to some extent. The
higher the temperature, the more algae will grow and the greener the water will
be. Your water will always be much clearer in the winter, as the algae does not
grow at low temperatures. Salt The increase of salt is also an option as it limits the growth of algae.
However, it also limits the growth of bacteria and pond plants if the quantity
is too much. Replacement of water Most people think that the quickest solution is to do more water changes or a
total water change, thinking that the clear water added will solve the problem.
The opposite happens. New water is rich in nutrients and the algae thrive again.
A lot of Koi keepers have leaks in their ponds forcing them to add new water on
a regular basis. These koi keepers always battle to keep their water clear. Patience In a lot of circumstances, you only need time. Any new pond will go through a
green phase despite the presence of a UV light. Be patient. It will probably
clear within a week. Let nature takes it's course. Nature is busy to create a
balance. If not, assist nature by doing something about it, and remember, if
there are also a lot of blanket weed, it might block your bottom drain and also
create a source for bad bacteria and Nitrites when they die off.
