Taking different depths of the garden pond into account when planning is particularly important so that your pool does not later appear to be an oversized puddle. Plants and fish also require different water depths to maintain biological balance.
What depth should a garden pond have?
The optimal garden pond depth varies depending on the zone: swamp zone (10-20 cm), shallow water zone (20-60 cm) and deep water zone (at least 90 cm). To keep fish such as koi in a species-appropriate manner, the water depth should be around 1.5 meters.
Land size, soil conditions, personal taste, intended use and of course costs are the main criteria when it comes to the size and therefore the depth of a new garden pond. In order to keep temperature fluctuations in the pool as low as possible - which in turn has to do with the desired ecological balance in the water - the garden pond depth should be at least 80 cm, and even better between 90 and 120 cm.
A replica of nature – the pond zones
As is usual in natural waters, the ornamental pond also has several zones with different water depths and different plants.
- Swamp zone: For the bank zone, a width of 30 cm from the inner edge of the pool is sufficient. A depth of 10 to 20 cm would be optimal, so that the edge can be decorated with low marsh plants and the bank area is additionally concealed.
- Shallow water zone: This area, which is at least 30 to 50 cm wide, should have a depth of 20 to 60 cm and should not be modeled with too steep a slope. There is space here for nutrient-hungry pond plants which, when arranged appropriately, minimize the risk of excessive algae growth.
- Deep water zone: In order to prevent rapid and complete freezing in the event of permanent frost, a minimum water surface of 2 m2 and a depth of at least 90 cm is recommended for this pond area. Water lilies, floating leaves or even underwater plants can be used here.
Pond depths for species-appropriate keeping of fish
Since the different types of fish react very sensitively to water that is too warm, it is essential to take into account a pond depth that corresponds to their natural lifestyle. Only with very small species or the well-known aquarium fish can you be relatively sure that they will survive an ornamental pond that has been frozen (NOT frozen) for over three months alive. However, you should also protect your mini pond over the winter with an ice preventer (€18.00 on Amazon) or additional ventilation.
Tip
If you intend to breed Japanese carp, you should plan at least a pond size of 6 by 8 meters with a water depth of approx. 1.5 meters. The koi, which are not easy to keep, feel most comfortable in a tank volume of around 60 m3.