The 9 Biggest Mistakes in Garden Pond Construction

The 9 Biggest Mistakes in Pond Construction

A garden pond is the dream of many garden owners. It invites you to relax and is a small biotope for numerous creatures. If the various pond inhabitants feel at home and want to enjoy their pond for a long time, they must avoid typical mistakes when building the pond. It all starts at the planning stage. You should think carefully about how you want to design your pond. Even before construction, you should check what factors can lead to mistakes. This article describes the nine most significant mistakes you should avoid when building a pond.

1. Prefabricated Pond – Not Suitable for Fish

The idea of using a prefabricated pond may be tempting. Only the soil excavation must be done so that the pond can be used. You can save yourself the time-consuming task of lining the pond with foil. You need to put a few plants and fill the water. The problem also lies in the fact that the prefabricated ponds often do not have a pump and filter because these ponds are usually tiny. If you want to put fish in the prefabricated pond, the pond becomes a torture chamber for them. The deepwater zone is not large enough. The fish do not have enough freedom of movement and are not well supplied with oxygen. Due to their small size, algae can spread quickly. Diseases of the fish and the tilting of the pond water during long periods of heat are pre-programmed.

2. Ignore the Water Table

Before creating a garden pond, you should find out about the local groundwater level. If you ignore the groundwater level, the groundwater can press against the pond liner from below and destroy the liner and the entire pond. Your detailed work, which has not infrequently extended over several weeks, will then have been in vain. Groundwater has enormous pressure.

To avoid this, you should check the groundwater level before you create your garden pond. Devices for measuring groundwater are available in hardware stores. On your property, you can check the groundwater level. This does not take long, but it is an essential requirement before you start building your pond.

3. Not Enough Pond Liner Purchased

A liner pond is much more costly to build than a prefabricated pond, but the effort pays off. A typical mistake lurks in the sizing of the pond liner. It is often too tightly dimensioned. Only a few centimeters of liner then protrude above the water level. A functioning capillary barrier in the bank area is then no longer guaranteed. The pond permanently loses some water to its surroundings. If you notice this mistake, you can only correct it by removing the water and the liner again, buying more liner accordingly, and starting over again.

The larger your pond, the more the liner should overhang the bank. It makes sense to have 20 to 40 inches (50 to 100 centimeter) of liner overhanging the bank.

4. Bank Created too Steeply

The bank is often laid out too steeply and even almost vertically to create as large a deep water zone as possible. This leads to several problems. The visual appearance is spoiled because a steep bank does not look natural. When the water level is low, the black film becomes visible. If the sun also shines in intensively, the foil can be damaged. For various animals, a steep bank often becomes a deadly trap. They fall into the pond and then can not get out.

You should slope the banks evenly and ensure that there is a sufficiently large bank zone everywhere, which then merges into the shallow water zone.

5. Pond Liner is Bare

If the pond liner is bare, this can not only affect the appearance of your garden pond. The liner can be damaged by UV radiation and by sharp edges of the ice layer in winter.

You can avoid this mistake by covering the pond liner sufficiently with soil and planting it. There are numerous options for the shore area. For variety, you can also add pebbles to the pond liner.

6. Ignore Safety

A critical factor when you create a garden pond is safety. This is especially true if you have younger children or if children are frequent visitors to your home. As a pond owner, you have a general duty of care. This includes fencing your pond, so it is not freely accessible to everyone. You do not have to erect a fence around the pond. It is often sufficient to fence in your property. However, you should fence your pond if you have younger children.

A moment of inattention can turn your pond into a deadly hazard. You can also child-proof your pond by planting thorny plants and larger shrubs or perennials around it. It would be best if you stepped down the shoreline. This way, people who fall into the pond can get out without assistance. However, this does not apply to more minor children. A water level of 4 inches (10 centimeters) can already be fatal for small children who fall into the pond. With a sloped or stepped bank, you can also make it easier for animals that fall into the pond to get out and avoid their death by drowning.

7. The Wrong Filter

You should not do without a filter in your garden pond if you want good water quality and avoid algae colonization. In its efficiency, you must adapt the filter to the volume of your pond. Furthermore, it would be best to think about the pond inhabitants when choosing the filter. The larger your pond is, the more fish live in it. The more powerful the filter should be. The fish need oxygen, but they also provide pollution with their excreta and uneaten food. Leaves falling into the pond can also cause contamination. During more extended periods of heat, a filter with too low a capacity can quickly cause the pond water to tip over.

Once you have purchased the appropriate filter, it is still important to place it correctly. Proper installation is vital for the filter to function correctly.

Additionally, you should invest in a pond mud vacuum to rid your pond of debris. In the spring and preferably in the fall, you should thoroughly clean your pond and remove the silt.

8. The Wrong Choice of Plants

Plants are a must for any garden pond because they provide clean water and counteract the formation of algae. The right plants are also important in the riparian zone. Many pond enthusiasts mistake planting cattails and other reed species in the riparian zone. While such reeds look very decorative, they can spread rapidly. This danger exists mainly in smaller ponds. The roots of reeds can quickly destroy the pond liner and cause your pond to lose water. You should only plant reeds if your garden pond is large enough and has a sufficiently large shore zone. For smaller ponds, various perennials, swamp iris, and shrubs are more suitable. Bamboo also multiplies and can cause similar problems to reeds.

For smaller ponds, plants in the riparian zone with low root growth and do not become overgrown are suitable. A colorful mix of plants is recommended. If you pay attention to the different flowering times of the plants, you can enjoy lush blooms throughout the pond season. Purple loosestrife, meadowsweet, or marsh forget-me-nots are not very demanding and well suited for smaller ponds. Such plants can also attract many animals such as bees, bumblebees, butterflies, or dragonflies.

9. Not all Water is the Same

When filling your garden pond, make sure you use the proper water. Tap water is quickly at hand when you want to fill up your pond. However, it is often too chalky and therefore unsuitable for fish and plants. A permanently intact ecosystem is often challenging to create with tap water. Rainwater is suitable for the garden pond. However, there is not always enough rainwater available. If you want to fill a larger pond, rainwater is not enough.

If you have no alternative to tap water, you should first perform a water analysis. Before putting fish in your pond, you should carry out water treatment and decalcify the water. You can use various additives to ensure that an intact ecosystem can develop.

A mixture of tap water and rainwater is well suited. Once your pond is filled, you should check the water values from time to time. It would help if you did this at least once a week during the summer months to prevent the pond from tilting. If the water values are poor, you should replace some water.


Before you create a garden pond, you should learn about possible sources of error to avoid them. It would be best to use a pond liner because a liner pond is much better for fish than a prefabricated pond. It would be best not to make the pond liner too tight and it would help if you did not make the bank too steep. For safety, the bank should be sloped or stepped. Special safety precautions are essential if you have small children. If possible, the liner should not be exposed. Before you create your pond, you should check the groundwater level. It would be best if you did not do without a filter. On smaller ponds, you should use only slow-growing plants for riparian planting. Tap water is often too chalky, but you can treat it for an intact ecosystem with suitable additives.

Florian Egert

I am Florian Egert, the owner of I live with my wife and two children in Germany in a small village in the countryside.

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