Algae is important for the biological functions in the garden pond. They serve as an important nutrient basis for micro-crustaceans and also contribute to the oxygen supply in the pond. However, if they multiply too fast, the ecological balance in the pond can be disturbed. The result: In the worst case, green water or unsightly coverings can seriously endanger pond inhabitants.
The term string algae does not refer to a biological genus or species, rather it is a collective designation for clustering, wadding or matting that is visible with the naked eye. String algae generally belong with the green algae that grow underwater on water plants, rocks and dead wood. Frequently they form long threads (up to 20 cm in length), however they can also occur as a cluster or in a fur-like manner or surface covering form. String algae particularly thrive in spring with the increase in water temperature and increasing sunlight incidence (growth starts at 2°C). Moreover, excess oxygen and excess nutrients due to a lack of plants in the pond promote the growth of these algae. Algae should be removed from the pond in good time; when they have become mixed with other plants, removal of string algae is much more difficult. Depending on the time of day, string algae in the pond will increase and float as mats on the water surface or sink and cover the pond floor. These algae are extremely adaptive and quickly develop a resistance to chemical toxins. Green and marshy water indicates algae infestation.
This type of algae occurs in all ponds; its growth should be kept in biological balance. The pond water can tip if algae growth is excessively strong. In this case they can form an algae slick that no longer permits light into the pond and thus prevents photosynthesis, which results in a lack of oxygen in the pond with fish and plants dying as the result. Basically they are an important component for a functioning pond; they serve as a natural food source for many microorganisms and they are a considerable producer of oxygen (they carry out photosynthesis).
Blue algae (cyanobacteria) are bacteria that merely resemble the external appearance of algae. They are found in every garden pond. Under certain circumstances (e.g. high nutrient content of the water, increase in nitrate values) they can multiply explosively. Frequently blue algae are also referred to as slime algae because they quickly form slimy coverings, which then settle on stones and plants. An oily film on the water surface and a strong odour are characteristic. Blue algae generate toxins to prevail against food competitors, e.g. pond plants. Over time this can also become a danger for people and animals, consequently a strong infestation should be countered with UVC filter technology and sufficient nutrient competitors.
Brown algae can multiply extremely fast through cell division and in a few weeks can generate a visible, brown covering in the garden pond. The slimy covering adheres to rocks and also water plants. The associated withdrawal of light frequently results in distress or death of affected water plants. Brown algae need silicic acid (silica). In addition they prefer areas where there is little light. Brown algae can be easily removed mechanically, in combination with sufficient sunlight and low-silica water this problem can be effectively and sustainably solved.
Red algae predominantly settle in salt water, the fire-red salines are particularly well known. However, some species can settle in fresh water. Usually strong infestation is indicated by a red tint of the water. This can, however, also be induced by strong iron content. The photosynthetic algae particularly thrive in ponds with strong water movement, high nutrient content (particularly phosphate) and strong sunlight. The red algae group also includes the stubborn brush algae and beard algae.
String algae can thoroughly destroy the good mood of many garden pond owners. The important thing is to first determine the water quality. To do this, there is the Pro Water Analysis set in the OASE pond care product line. Or for fast, simple, and reliable water analysis of the 6 most important water parameters the QuickSticks are available. You will quickly determine that a situation of excess nutrients prevails in water infested with string algae. In addition to the nitrogen compounds, high phosphate values are also particularly critical.
Excess nitrogen compounds (e.g. nitrite, ammonium) can be sustainably reduced with biological activation of the filter system. Additional information concerning the biological fundamentals is provided here.
The use of PhosLess Filter Inserts helps against excess phosphate values. The special fillings specifically withdraw the phosphate, and thus a crucial algae nutrient, from the pond water.
Nutrient-regulating measures take their time and thus should be initiated on a preventative basis. Regularly empty your skimmer. Ensure that your filter system is adequate. The combination that is suitable for your garden pond or watercourse essentially depends on the size of the pond, i.e. water volume and fish stock.
If there is acute need for action against algae that is taking the upper hand, the use of AlGo Universal from OASE is recommended. This algae control agent inhibits photosynthesis of algae and allows it to die off incrementally. Also AlGo Direct can be used in watercourses or on pond edges that can be reached. Through direct contact with string algae destroyer, fast local elimination of the green pest is ensured.
Help your pond to help itself - the AquaActiv pond care product range ensures sustainable, clear, living water with optimal values and healthy fish.
Simple product selection in the new AquaActiv 4-step plan makes it even easier to effectively prevent and eliminate algae. The Step A and Step B products prevent excessive algae growth by stabilising the water quality and eliminating excessive nutrients. You should only use Step C products if treatment with Step A and Step B products is unsuccessful.
In filter and pond our starter cultures ensure the crucial kick that is vital for the biological balance of the body of water.
For proper treatment of different water qualities – based entirely on the needs of your pond or water pool.
Particularly effective against nutrients, pollutants and other undesired residues!
If steps A and B are not successful.
Bio-film formation, microorganisms or algae growth on the surface can cloud the enjoyment of the modern water garden. Correctly dosed, the OASE disinfection products keep bodies of water such as swim ponds, architectural pools or ornamental fountains clear and fresh. However, ensure that these agents are not used on fish ponds or biotopes.