The garden pond or the swimming pond are the figureheads of a garden or a plant. Especially in the swimming pond there should not be any visually disturbing algae that can also hinder swimming.
Algae can usually be recognized by their slightly greenish shimmer. In most cases these are caused by green or blue algae. With these two types of algae, however, the water remains clear. Water fleas can be used here in garden ponds. These are harmless to humans. However, you really have to worry if the pond or swimming pond is infested with thread algae. With thread algae it can happen that they cloud the water when they multiply very strongly. Other plants that are in the pond die and consequently sink to the bottom of the pond. These begin to decompose on the bottom. Decomposition processes start now, which leads to a decrease in the oxygen concentration in the pond. The water can tip over and fish that are in it even die.
Algae species that are found in the garden pond
There are a large number of different types of algae in garden ponds or swimming ponds. In addition to various green and blue algae, the thread algae, microalgae and floating algae also occur here. As a rule, they live there, insofar as the nutrient concentration of the water is optimal or normal, in coexistence with many fish and plants. However, if the phosphate concentration rises above 0.035 milligrams per liter, the living conditions become the
Algae extremely improved. If there is also exposure to the sun, the algae can multiply explosively. This explosive growth is called algal bloom. This algae bloom ensures that other living things in the pond can no longer receive the nutrients they need.The role of phosphate in the pond
Phosphates can get into swimming ponds and garden ponds in very different ways. Most of the time, however, it is the phosphates from fish feed that cause an excess of phosphates. Many types of fish such as bitterlings, goldfish or sticklebacks find enough food in the pond to survive without additional food. If there are only such types of fish in the pond, additional feeding, as is the case with koi, for example, is not necessary. But also in the fish droppings, which like the excessive feed, sinks to the bottom of the pond, there are phosphates. In addition, these can also get into the water via fertilizers or during heavy rainfall. But leaves and dead plants that sink to the bottom of the pond also contain phosphates, albeit only in small amounts. However, it also contains other nutrients that ensure increased algae growth.
Remove the nutrient medium from algae
Problematically, it is not just the algae that need phosphates to thrive. Other living things in the pond are also dependent on phosphates, nitrates and other nutrients. In principle, it can therefore be assumed that plants in the pond do
Claim phosphate and the other nutrients for themselves. In order to remove these plants from the nutrient cycle, the aquatic plants have to be cut back. However, the clippings should not remain in the water, as this sinks to the bottom and rots there.Algae in the pond should be fished regularly. These can also be composted. Mineral phosphate binders can also be used to reduce the phosphate content. Chemical processes ensure that the phosphate is bound with the minerals and can no longer be absorbed by the algae. If there is too thick a layer of sludge on the bottom of the pond, renovating the pond can help. To do this, the water is let out of the pond and the thick layer of sludge, which consists of rotten plants and fish droppings, is removed. This sludge layer is now replaced by a nutrient-rich substrate. Here, too, the plants are cut back.
Keep pond water permanently clear
If you want to have a permanently clear, algae-free pond, you should ensure that all sources of phosphate are removed. Most of the time, the course for this is already set when the pond or swimming pond is set up. A slightly elevated place should be chosen to create the pond, even if it does not look natural. This slight increase prevents fertilizers from the environment from being washed into the pond. A 50 to 100 cm trench acts as an additional buffer. Coarse-grained construction sand should be poured into this trench. In addition, the location should be chosen so that it is in penumbra. Sunlight does not directly increase the amount of phosphate in the water, but it does promote algae growth. In addition, the diameter and depth of the pond and the bathing pond have an influence on the formation of algae. The shallower and smaller a pond, the more often problems with algae occur. The pond soil should consist of nutrient-poor sand. The water with which the pond is filled should be checked and should contain less than five milligrams of phosphate per liter of water. Nutrient-rich deposits in the pond should be removed with a pond sludge vacuum. In autumn it can be useful to cover small ponds with a net. So no falls
Leaves in the pond or bathing pond.Keep the phosphate content in the fish pond low
Aquatic animals such as fish or newts produce excretions that also contain phosphate. As a rule, these excretions are harmless. However, if fish food is too fed, additional phosphates and other nutrients get into the pond, which can also be absorbed by the algae. For this reason, only as many fish should be kept in the pond as this pond can feed. If you still need to feed, the installation of additional filter systems can help that algae and the excess nutrients are removed from the garden pond. This is especially the case with fish, such as the Koi fish, since additional feeding cannot be dispensed with here.
Interesting facts about biological algae control
If the outside temperatures are already higher at the beginning of spring, this is normal and only low If precipitation occurs, there is usually a risk of increased algae formation in the ponds of the local population Gardens. This observation can even be made in biotopes with a rather low oxygen or Nutrient content can be made. The following are particularly widespread:
- Yoke algae,
- Thread green algae
- Blue-green algae
For the owner of an artificially created biotope mean Seaweed mostly nothing good, on the contrary: a lot of work combined with a high expenditure of time, some of it annoying, green growths from the water and from the other plants (water lilies etc.) as well as the (stone) border remove. But what must be done to put an end to the algae growth?
- UVC devices are a biological and also quite efficient solution, but they are suspected of causing cancer.
- The complete renewal of the water in the garden pond is certainly more complex, but many times more effective.
- Algae-eating fish species are ideally suited to contain the excessive algae population!
- Nutrient-consuming aquatic plants, such as B. Echinodorus or the Cryptocoryne.