The garden pond is a popular project. Water, regardless of whether it is flowing or standing, has a fascination for people, something that is made possible without any problems by having your own pond. In addition to the selection of plants and creatures, not only the shape or the access to the stream, but also the pond floor are important for planning the pond. Here you can find out which substrate is suitable as a substrate.

What is the pond floor?

The subsurface is understood to mean the substrate that is distributed on the pond liner or the building materials used before the water is let in. Its function is not only to provide support for plants, but also to provide a home for fish that need substrate. The pond substrate is just as important as potting soil for flowering plants and must therefore be integrated into the planning. With the right subsurface, the plants and fish feel really good in the garden pond and can adapt to the artificially created realm.

Tip: Even for a swimming pond, you have to plan the substrate so that it is not stirred up by people and distributed throughout the pond. For this reason, a different pond bottom is selected for this than for a natural pond or a body of water for Kois, for example.


It is substrates that make a garden pond with animals and plants possible. If you opt for a pond without a subsurface, it is reminiscent of classic fountains and water systems, such as are common in castles or museums. Such a pond naturally looks out of place in your own garden, unless it is a landscaping project. Plants, fish and other pond dwellers, however, need a nutrient base and a way to attach themselves to the bottom. This is where substrates come into play, which make the garden pond an ideal habitat for living things. The classics include sand, clay and gravel.

Tip: As an alternative to the typical variants, ready-mixed pond substrate is offered, which is geared to special projects. There are not only pond soils for keeping different fish, but also for natural, swimming or mini ponds that simply fill the pond and have to be replaced every now and then.


Just as sand is a typical component in all rivers and lakes, it is well suited for your own garden pond. However, not all sand is the same, especially when it comes to a pond. Grain, texture and the combination with other components defines the purpose of the sediment. Sand mainly comes in four varieties:

  • fine sand: ideal for pond plants, accumulates sufficient nutrients, not suitable for fish
  • Coarse sand: ideal for fish, is not so easy to stir up, also suitable for plants
  • Sand and clay: perfect for small ecosystems, can be laid precisely
  • Sand and gravel: a good mix for fish and a few plants

Sand as a pond floor should always be tailored to the intended use. For example, if you are creating a large garden pond and want to keep a lot of fish and plants, a clay-sand mixture is always recommended as a substrate. The sand provides the necessary nutrients, while the clay provides the necessary hold. For example, many fish can hide in the bottom and over time the nutrient content adapts to the ecosystem in the pond. Sand is also easy to change when necessary.

Tip: When choosing the sand, be sure to pay attention to the color, as this has a significant effect on the overall appearance of the garden pond. If you use an almost white sand in a shady corner of the garden, the pond catches the eye and could look out of place, which of course also applies to the gravel used.


Gravel is a popular alternative to sand, but you have to be careful here. Gravel often leads to damage to the pond liner, which is of course undesirable. Gravel is therefore only used as a substrate in two ways:

  • Ornamental gravel : decoration of the bank areas, less often in flower pots planted directly in the water
  • fine gravel : ideal for plants

Since gravel releases only a few nutrients into the garden pond, the water remains clear and is not contaminated as quickly as with sand. Therefore, plants can settle in well in the pond. When using gravel, be sure to wash it before pouring it. This means that the water is less polluted and there are no small objects in the garden pond that could have a negative impact on the plants and fish.

Tip: Do not confuse gravel with lava chippings when applying, as these two substrates are used for different purposes. Compared to gravel, lava chippings are not used for the establishment of classic pond projects, but for the implementation of a swimming pond, since the volcanic rock with its surface provides a good hold for aquatic plants and is not easily stirred up.


With clay, there is a subsoil in the garden pond that solidifies quickly and is only slightly stirred up. Clay is always used together with sand or pond soil and can be used to hold fish and plants at the same time. When choosing the substrate, you should only use brown clay powder, as this is best suited for the pond and can be laid without any problems. Since clay stores high amounts of nutrients compared to sand and gravel, even very hungry plants such as cypress-sedges (bot. Carex pseudocyperus) can be cultivated.

Creating a pond floor explained briefly

As soon as you have decided on a substrate as the subsurface, the pond is filled to 30 percent with water in order to compact the pond floor. The pond liner also tightens through the compaction, which makes it easier for plants to plant. This is because these are set into the substrate a short time after the water has been let in. These are plants of the deep water zone that are later no longer so easily accessible. At the same time, electronic and mechanical components are placed in the pond, such as the pump or water features. Then it is filled and the remaining plants are used. Compaction is particularly important in sandy soils.

Tip: It is important to plan ahead when using substrate. You should never equip a garden pond with a bottom drain with substrate, as this could clog up.

Conclusion: The
pond floor is essential to enable plants and fish to have a home in the garden pond. Since the right substrate can be found for every type of garden pond, small ecosystems can be implemented that fit nicely into the garden. If safety instructions such as the grain size of the gravel are observed, nothing goes wrong with the implementation.

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *