Build a koi pond yourself – pond construction instructions

Yes, a koi is really just a very simple carp, but a “carp with style”: The koi is a special breed of carp that was originally developed in Japan and was cultivated for a long time Bred colors that can give great value to an individual Koi. The size of the koi also plays a role in its value, and only if the conditions are ideal will a koi grow to its maximum size and develop particularly beautiful colors. The koi have an astonishingly high life expectancy, they can be about the age of a human if they are well kept, around 70 years, there are even koi that are said to have reached 200 years.

Koi should only be kept in the koi pond

If you have fallen in love with the trusting koi and you absolutely want to call such fish your own, you will not be able to avoid creating your own pond. Theoretically it would be possible to keep koi in the aquarium, but that would have to be an extraordinarily large aquarium, as koi grow quite large and like to swim around. Even in a normal, large aquarium, the koi do not have enough space, which means that keeping them is no longer appropriate to the species, and according to our animal welfare law, this is considered to be animal cruelty.

This is the reason why Kois are usually kept in large ponds specially created for them, in a natural pond the fish should feel most comfortable and thrive best. The pond has to be large because keeping koi in a species-appropriate manner also means keeping a whole group of these fish. Koi carp are not loners. At least four to five koi should populate a pond, and each koi carp should be able to claim around 1,500 liters of water. This is not an arbitrarily chosen or unimportant number, only with this amount of water the Koi remains healthy, experience has shown that any over-dense population causes diseases or parasite infestation at some point.

The right location for a koi pond

There are a few things to consider when determining the best location for your future Koi pond in your garden:

• As I said, you should calculate around 1,500 liters of water per planned koi, so with four koi as a minimum, the pond must contain at least 6,000 liters of water.
• The private keeping of Koi is only practicable if the fish live in the pond all year round, otherwise we would be back to the topic of giant aquariums for wintering.
• If you’ve heard that koi can be hibernated in large quarantine basins in basements, you’d better not pursue this idea.
• Every change of location is serious stress for the animals, usually leads to diseases or growth difficulties, you will definitely not keep happy koi like this.
• So that the koi can stay in the pond in winter, a water depth is required that guarantees frost-free zones even at sub-zero temperatures.
• The minimum depth for ponds that do not freeze through is 1.30 m, a water depth of the Koi pond between 1.80 and 2 meters is recommended.
• Because the depth of 1.30 m would have to be maintained over a very large area so that the fish has enough freedom of movement when the water surface is frozen.
• If the pond is planned deeper, the frost-free zone does not have to be as large as that, the entire pond thus has more realistic dimensions.
• We are still not talking about small ponds, the smallest koi pond will take up an area of ​​around 25 square meters.
• The more koi you want to keep, the bigger the pond needs to be.
• Like any pond, a koi pond should not be in the sun or in the shade all day.
• As is so often the case, a location in partial shade is the best prerequisite for a balanced living environment, also by the pond.
• It depends on the location, depth and shade of the pond whether you can always provide the koi with optimal water temperatures.
• A Koi would like to have water around him at 14 to 18 degrees in spring, in summer it can be 20 to 26 degrees and in winter it can be a maximum of 4 degrees cold.
• This can only be guaranteed for ponds of the recommended depth, size and location.
• The pond should also not be placed under deciduous trees, because any fallen leaves must be fished out of the pond later.
• So you need a shade for the pond, under which the water quality does not suffer. B. transplanting with bamboo or china reeds.
• For these large grasses on the edge of the pond, you have to plan enough space when choosing the location.
• Calibration instructions for building a koi pond yourself

The following points must be observed when building a Koi pond:

• Before you start digging the pond pit, you must of course decide whether you are going to use pond liner or a prefabricated pond.
• Prefabricated ponds are ready-made pools that are quite easy to install.
• With every prefabricated pond, you can receive the data on the amount of water, water depth and frost-free amount of water when you buy it.
• The pit is also quite easy to excavate here, in which the prefabricated pond is then only inserted in accordance with the regulations and instructions.
• However, you are more likely to work with pond liner for a koi pond, pond basins of this size are really expensive.
• A pond pit that is to be lined with pond liner must be calculated, but nothing to be desired in terms of shape.
• In this case you should have the size, depth and slope of the pond calculated by a specialist if in doubt.
• This should be done with separate identification of the total amount of water and the amount of frost-free water in winter.
• In the course of this calculation, a plan is created for what your excavation should look like.
• In any case, it will be a considerable amount and borrowing a mini excavator is certainly recommended.
• When the pit is finished, handwork is the first thing to do:
• The more carefully you remove everything from the bottom of the pond pit that could later damage the liner, the longer your pond will last.
• A protective layer of sand and a root protection film are then placed under the film, follow the instructions of the film manufacturer
• Now the pond liner is laid out, also in strict compliance with the manufacturer’s instructions, otherwise you will not have any guarantee claims in case of doubt.
• When the pond liner or pond basin is in place, both are allowed to sit down for a while and adjust to the temperature of the environment.
• Then the pond floor is filled in, and next you can start planting the pond.

And what about pond technology?

Here we give you instructions on how to create a natural pond for Koi, in which a self-regulating biotope will form with the right planting. Such a natural pond can be maintained with reasonable effort if it is stocked with adult Koi. So you can z. B. can usually be seen with the naked eye whether the water quality is OK.

If you want to create a breeding pond for koi with young fish rearing, this is no longer a hobby, but a profession, and accordingly an article “Instructions for pond construction” will no longer be enough. Such a pond has nothing to do with relaxation in the garden, but requires a lot of maintenance and the use of a lot of pond technology.

Unless you want to depend entirely on pond technology dealers who can tell you what they want, you will need to learn a lot about pond technology before setting up a farm pond. In a pond in which young Koi are raised, usually no natural conditions are maintained, but one works with crystal clear water, the water values ​​of which must always be in a certain ideal range. The water quality has to be measured continuously, the risk of pollution is much higher than in a pond with adult fish because the young fish have to be fed frequently.

If, on the other hand, you only populate a large natural pond with so many fish that it is not overcrowded, it is theoretically even conceivable that the koi will feed themselves in the balanced biotope. However, since koi are quite large and bring in quite large amounts of excrement, the use of a pond filter is recommended in addition to filtering and cleaning plants. You should get advice from a specialist on site about its shape and size when the pond planning is in place.

The correct planting of the koi pond

There is a very large selection of aquatic plants and bank plants that perform all filter functions and must be introduced in certain quantities. They are there to ensure good water quality and prevent extreme algae formation. In addition, the aquatic plants ensure that your pond looks really romantic, wild or simply naturally beautiful, depending on the planting.

You should put together a planting plan for the pond in advance, in which you put together the pond planting with regard to the filter function to be performed. You will find a lot of information about aquatic plants and good combinations of aquatic plants in a natural pond, but you should always pay attention to whether this information specifically refers to planting a koi pond.

There are a few things to consider when choosing plants for the koi pond. B. not survive long, but be consumed by the koi on the spot. Other plants, on the other hand, are very suitable for a koi pond, e.g. B. Water lilies, which are much more robust than they appear. In addition, some plants have certain advantages. The water lilies protect the koi with their large leaves, for example. B. in the summer before sunburn, which occurs quickly with koi, if you have overdone it with pond maintenance and the water is very clear in a hot spell.

Cleaning and care 

If your planting is right, your pond should, under normal conditions, have good water quality almost by itself. Almost by itself, because even the best water-purifying pond plants cannot prevent dead plant parts from falling into the pond, which you have to remove.

You must also expect that the balance in the natural pond will regularly reach its limits. B. aquatic plants are pruned, the water should be changed once or twice a year, every few years the pond floor will probably also need a so-called renovation, i.e. a complete change of the soil layer enriched by many rotten plants. The water can be a little cloudy, the Kois also want to withdraw from time to time, but if the water turns too green, you should take care measures.

By the way, there is a trick to prevent unwanted plants from getting in: you stretch a net over the pond, which can hardly be seen, but which catches falling parts of the plant. This trick is sometimes highly recommended, and always when you have a lot of cats roaming around and your koi are really trusting, then the cats like to fish the koi out of the pond, which are just below the surface of the water. Herons that strike from above should also be deterred in this way, but you should find out exactly which net poses no danger to these animals.

Conclusion
The natural pond is the easiest to create and the easiest to care for koi pond. You just have to develop an eye and a feeling for the water quality, which in turn is quickest if you can consult with another natural pond owner nearby.