The Content Of The Article:
- Algae are not algae
- Where do the algae come from?
- Remove the nutrients from the pond water
- Tips for the pond system
- Proper care for an algae-free garden pond
- Problem fish pond
Have you ever noticed a greenish glow in the water in your garden pond? These are microscopic green or blue algae. But they do not disturb the aesthetic impression of the pond, because the water remains clear. In addition, these algae are easy to keep in check with water fleas. The tiny floating crabs feed on them, so over time a biological balance sets in. In contrast to real fleas, water fleas are completely harmless to humans and also welcome help in the swimming pond for a good water quality. If green algae multiply too strongly, they usually deposit as tough mucus on the water surface and can be removed relatively easily.
Algae are not algae
Pond owners are especially worried about the larger filamentous algae. They lead with strong increase to the fact that the water completely clouded. After this so-called algal bloom, the plants die and sink to the bottom of the pond. Due to intensive decomposition processes, the oxygen concentration in the pond water sometimes drops so much that the fish suffocate and overturn the water.
Where do the algae come from?
Each pond has a variety of algae species. As long as the nutrient concentration in the water is normal, they live in peaceful coexistence with other plants and fish. But if the phosphate content rises to over 0.035 milligrams per liter, improve their living conditions. If the water temperatures and the sun rise, they multiply explosively - it comes to the so-called algal bloom.
Lack of oxygen and a rich supply of nutrients can trigger an algae bloom
Phosphate and other nutrients enter the garden pond in various ways. The most common source of phosphate is fish droppings and excess food, which sinks to the bottom of the pond and is decomposed into its components. In addition, during heavy rains, lawn fertilizers or nutrient-rich garden soil are often flushed into the pond. The leaves, which enter the water in autumn, also contain small amounts of phosphate and other nutrients that promote algae growth.
Remove the nutrients from the pond water
Not only the algae need to grow phosphate, nitrate and other nutrients, but also the aquatic plants. The more plants that live in your pond, the faster the nutrients are bound by plant growth. In order to remove these from the nutrient cycle of the water, you must cut back the water plants from time to time. You can then dispose of the clippings on the compost.
With the "Algae Witch" thread algae can also be caught between aquatic plants
The regular fishing of algae also reduces the nutrients in the pond. The algae are excellent composting like the aquatic plants. Even with mineral binders (phosphate binders), you can lower the phosphate content of pond water. The nutrients are bound by chemical processes, so they can not be absorbed by the algae, nor by the plants.
Most of the nutrients you remove from the water with a renovation. Remove the so-called Mulmschicht from fish manure and decayed plants and replace the old Teicherde by new, nutrient-poor substrate. All plants are vigorously cut back, split and then placed in new, low-nutrient ponds or without substrate in special plant baskets or embankment mats.
Tips for the pond system
To keep the pond water clear, you must eliminate all sources of phosphate. The course for this is already made at the plant of the pond. The most natural effect of the water, if it is in a depression - but this carries the risk that garden soil and fertilizer can be washed into the pond. Therefore, choose a slightly elevated space or surround the water with a 60 cm deep drainage ditch, which you fill with coarse grained sand.
When setting up your pond you should make sure that the pond also has enough shady spots
Although the lighting conditions do not affect the phosphate content of the pond water, sunlight promotes algae growth. Therefore, choose a location that is at least one-third in the shade. Also, the amount of water and depth of water play a role. rule of thumb: The smaller and shallower the waters, the more common are algae problems.
Use as nutrient-poor sand, and as little as possible of it. As a pond water you should only use certified tap water, because many water utilities enrich the drinking water with up to five milligrams of phosphate per liter to reduce corrosion in the pipes.The waterworks often publish their water analyzes on the Internet or send you the corresponding documents upon request. If the tap water contains too much phosphate, you should treat it with phosphate binder. Groundwater is usually low in phosphate and therefore more suitable. Optimal is rainwater, because it is free of minerals. However, very few hobby gardeners have the corresponding amount available.
Proper care for an algae-free garden pond
Even in clear garden ponds, nutrient-rich deposits form over time. These can be removed with a special pond sludge sucker. In addition, it is best to cover smaller ponds in autumn with a net, so that no leaves fall into the water. In order to remove floating foreign bodies such as pollen or the like from the pond surface, there are also so-called skimmers, which suck the water at the surface and lead into a filter system.
If you keep large koi carp in your garden pond, you need a good filtration system
Problem fish pond
The excretions of fish, newts and other aquatic animals naturally also contain phosphate. This is not so bad as long as the animals have to live off what they find in the pool of food. However, if you regularly feed them with fish food, additional nutrients enter the pond from the outside. There are two ways to prevent a fish pond from falling over: Either you use so few fish that you do not have to feed, or you install a good filtration system that removes algae and excess nutrients from the pond. Especially with large fish such as the magnificent Japanese koi carp you can not do without powerful technology.