© Stefanie Prinz
Although beard algae belong to the red algae family, they form long, dark green threads. They attack plants as well as furnishings and decorative parts in the aquarium. Apparently the edges are particularly preferred.
Beard algae are therefore often found on the leaf edges of aquarium plants and are also discovered there by many aquarists for the first time.
They also like to settle in places with strong water movement and high oxygen levels.
Causes of beard algae
As with almost all types of algae, there is a suspicion of an imbalance in the nutrient balance if there is an accumulation of beard algae. This can be either an excess of nutrients or an undersupply of nutrients. If the beard algae appear almost exclusively on the edges of older leaves and not on the ground or decorative objects, this can indicate an excess of nutrients. In many aquariums, regular fertilization, especially with liquid fertilizers, brings in more nutrients than the plants consume. Since increased infestation with beard algae has been reported several times after fertilization with liquid fertilizers, the ingredients of these liquid fertilizers may also be a cause.
No products found.
Too sparse planting of the aquarium with too few and above all too slow-growing plants can lead to an oversupply of nutrients. The excess nutrients are absorbed by the algae and the algae multiply explosively in some cases.
If there is a lack of nutrients, the plants do not receive all the necessary nutrients in sufficient quantities. Due to the deficiency, plant growth stagnates as a result. The total consumption of nutrients is based on the nutrient that forms the bottleneck and not all of the other nutrients are consumed. These then benefit the algae, which can spread accordingly.
Other possible causes can also be conditions in the area surrounding the aquarium, for example excessive lighting or direct sunlight.
If one of the mentioned conditions is present, then often a small change in the overall conditions in the aquarium will lead to a sudden infestation of algae. In particular, changes in the lighting due to new tubes, additional sunshine, etc. can be the trigger for this.
In order to eliminate the algae permanently, it is therefore essential to determine the real causes of the algae plague.
Unfortunately, the causes and countermeasures listed here can only provide guidelines. There can be many different causes for an infestation with algae. In some cases it takes a very long time until the causes and thus the appropriate countermeasures are found. With time and increasing experience in aquaristics, however, you get a feeling for how an aquarium can be kept in balance and what measures have to be taken when the different types of algae appear. You also get to know the requirements of the different types of algae over time.
Measures against beard algae
sit out
According to one report, beard algae can be grown into long beards in newly set up aquariums and then fished off. After about 12 weeks they die off and stay away permanently. According to this report, beard algae no longer appear in older aquariums (from approx. 9 months). However, according to other reports, beard algae do occur in older aquariums. It has been repeatedly reported that beard algae appear cyclically in some aquariums and then die off by themselves.
Change filter outlet
If the filter outlet is above water, laying it under water can reduce the oxygen input. If the outlet is just below the water surface, it should be placed deeper in the water. Throttling the water flow also reduces water movement, especially on the surface, and thus the oxygen input.
Eliminate excess nutrients
If there is an excess of nutrients, the excess nutrients are removed as a first step by changing the water extensively. A daily water change with 3 – 4% reverse osmosis water has also proven to be effective. As a result, the input of nutrients is reduced, e.g. B. introduced less fertilizer.
At the same time, fast-growing plants should be planted in the aquarium, which absorb the excess nutrients before the algae can use them. Water mermaids (Cabomba), waterweed and tomentosum have proven to be suitable against beard algae. Hornwort in particular is very popular with many aquarists for this purpose.
However, the use of fast-growing plants can only be effective if the overall conditions for the plants are good. If the plants grow poorly before the algae infestation, further planting will of course not help at first. However, if you eliminate the cause of the poor plant growth, the cause of the algae infestation is usually also eliminated.
Fast-growing plants help against algae for the following reasons:
- They remove superfluous nutrients from the water, if available.
- They shade the aquarium, especially floating plants or floating shoots
- They produce oxygen
Eliminate nutrient deficiencies
In the case of beard algae, particular attention should be paid to ensuring that there is a sufficient supply of CO2. It is said that beard algae do not appear if there is enough CO2 in the aquarium. The CO2 consumption in the aquarium is mainly determined by the CO2 input and consumption by the plants. The number and growth rate of the plants therefore play an important role. Other metabolic processes, such as the respiration of the fish and gas exchange on the water surface, usually play a subordinate role. If CO2 is used as fertiliser, the correct setting of the required CO2 quantity must be checked.
Other important nutrients are nitrate, iron and phosphate. The use of an NPK fertilizer, e.g. B. Mairol liquid fertilizer proven.
Combat and prevent beard algae with humic acid
The growth of beard algae can be dampened by humic acids. These form either in the filter sludge or in the sludge on the ground as a result of bacterial decomposition processes.
Humic acid can also be introduced with the help of peat. For this purpose, approx. 1 liter of peat per 100 liters of water is brought into the aquarium in a Perlon bag. The peat stays in the water for a week and is then replaced with fresh peat. The peat used should be highly acidic and of course not come from ecologically contaminated sources. As a test, you can soak a small amount of peat in distilled water. The pH value measured afterwards should be well below 4.
With this measure, care must be taken to ensure that the water in the aquarium is changed by the peat, even if only insignificantly. The fish stock must of course be able to tolerate the new conditions.
external causes
If the sun is too strong, the window can be covered with foil, existing roller shutters can be lowered or a lunch break can be introduced for the lighting. While lunch breaks aren’t usually particularly effective against red algae, it can be helpful when there’s too much lighting or exposure to the sun.
Removing the beard algae
Older leaves with beard algae on them are removed, and the algae on the other leaves are rubbed off as much as possible with thumb and forefinger. You can also try winding up the algae with a thin, rough stick. If echinodors are infested with beard algae, the leaves can be cut off directly above the root stalk if the infestation is severe. Otherwise, new leaves can also be attacked within a very short time (1 week).
The purpose of these measures is to prevent young algae from growing back and to gradually remove existing algae from the aquarium by removing the old leaves. The removal of old leaves in particular must be done with a sense of proportion, as depending on the infestation of some plants too few leaves may remain. In these cases, only part of the old leaves are removed. Then you wait until new, algae-free leaves have grown back. Only then are other old and affected leaves removed. The final elimination of the algae can therefore extend over a longer period of time. It is important that no new algae grow back during this time.
In an unusual and previously unrepeatable case, the beard algae fell off the leaves within a short time after an iron deficiency was corrected by the addition of Fetrilon.
The sudden elimination of the iron chlorosis caused by the iron deficiency may have been the cause. This may have benefited from the fact that very little fertilizer was used in the affected tank.