The word “algae” comes from Latin and means “seaweed” or “kelp”. There are both microscopic single-celled organisms, also called microalgae, and macroalgae: These are seaweed that can grow to be over 50 meters long. Due to the photosynthesis that algae constantly perform, they produce oxygen that is essential for life. Apart from the fact that they serve as a source of food for many other creatures – including in the aquarium. Nevertheless, they have the negative characteristic of spreading too quickly and too uncontrollably. They attack the glass panes, stones and filters. A horror for aquarists who especially value the view of their bred flora and fauna. The question arises as to how you can prevent algae from spreading uncontrollably in the aquarium without completely removing it?
In theory, it is impossible to remove all algae – no matter how small – from the aquarium. And that’s a good thing so as not to destroy the ecological balance. Especially in the first phase, when you have just bought a new water tank, algae growth is unavoidable and later absolutely necessary for the flora and fauna in the aquarium. However, once the new setup is over, there are a few things you can do to keep the water at least apparently free of algae. This is much easier than clearing a pool that is already full of algae – which especially happens if you have added too many fish, added too much food or changed the water too rarely.
You don’t have to get out the chemicals straight away to get control of the algae. Especially in the unstable start-up phase, when the biological balance has not yet been established, you can use algae-eating Amano shrimp or racing snails as well as fast-growing stem plants to keep algae growth under control. You should only let the first fish into the water when so-called filter bacteria have formed. The location is also an important indicator: the more direct sunlight enters the aquarium, the faster the green threads bloom and thrive. But too strong or weak lighting can also help the algae grow faster.
If the algae in your aquarium have gained the upper hand after it has been set up again or even after a long period of inactivity, there may be an imbalance in the water. In order to find out why the algae feel so comfortable in the tank, you should first identify them – this is the only way to combat them effectively. In addition, a water analysis is recommended to find out whether there is a nutrient deficiency that the plants need, for example, to grow: nitrate or phosphate, for example, are essential for an ecological balance in the aquarium. If there is a lack of nutrients, algae can spread unchecked.
Brush algae are particularly stubborn. As the name suggests, their bushy shape and dense threads are reminiscent of a brush. Even though they belong to the red algae family, their color tends to be dark green to black. Since they mainly make themselves at home on leaves, the infected plants must be completely disposed of – unfortunately selective removal is not possible. To combat them, you can keep guppies and platies in the aquarium.
Bearded algae belong to the same family and owe their name to their bearded appearance. They also tend to stick to aquatic plants, filters or decorations and are difficult to remove. The most effective thing here is to clean the infected equipment, change the direction of flow and remove the affected leaves – if the infestation is severe, it is also advisable to remove the entire plant from the aquarium.
Green algae mainly spread when there is an excess of nutrients in the water. You can recognize the infestation on the windows of the aquarium when furry deposits that look like long, green threads settle on them. To permanently combat the algae, you can put the following animals in the basin: racing snails, limpets or antlered snails as well as antenna or catfish. Alternatively, a magnetic window cleaner is extremely helpful.
Blue-green algae also covers stones, plants and decorative materials in the aquarium with a slimy, blue-green coating. They spread especially when the water quality is poor – here too, a water analysis is recommended. If the nitrite and nitrate content is particularly high, blue-green algae feel extremely comfortable. Suction catfish and snails, among others, can help here. Chemical algae agents are even more aggressive.
Diatoms have a brownish appearance and are therefore more often confused with brown algae, which, however, only occur in the sea. In the aquarium, on the other hand, the annoying inhabitants can cover all surfaces – this happens more often after the tank has been rebuilt and resolves itself over time. However, if the diatoms persist, this indicates poor water quality.
Thread algae cover plants and decorations in the aquarium with long threads that can be easily pulled off by hand. These can be removed even better using a thin stick – as they don’t really stick to the surfaces, they just cling to them. If you don’t want to remove the green threads manually, you can also resort to the algae-eating shrimps that love thread algae.
Easy Life AlgExit is said to help best against green, thread, beard and brush algae. It not only ensures that the advancing algae growth is stopped, but also that the algae disappear and any remaining algae spores are removed – but the chemical club also has a catch: not all types of fish or shrimp can tolerate the agent. For this reason, you should pay attention to the packaging instructions.
Tetra Algizit is also said to be an effective remedy against algae – although it is not entirely clear which types of algae the product is suitable for. According to customer opinions, the product is said to help primarily against blue and beard algae. The ingredient is available in both tablet and liquid form. The release of active ingredients promises a quick result, but customer opinions vary here.
The same applies to the AQUALITY Aquarium Algae-EX, which promises quick and effective help with algae of all kinds. The agent is added to the water over a period of four weeks and, in addition to removing the green threads and streaks, is also intended to promote plant growth. And all without copper and other heavy metals.
To prevent your aquarium from developing an algae problem, you can take some preventative measures. In addition to the location already mentioned, the water quality, the amount of food and the number of fish, these include the size of the basin, the carbon dioxide content and the filter system. The individual points are explained in more detail below:
The size of the aquarium
In fact, the size of the aquarium has a significant impact on how quickly algae spreads within it. The larger the tank, the less algae forms in it – or so experienced aquarists say. Of course, it always depends on how “full” the water is: the more fish and plants, the higher the risk of an algae plague. For this reason, newbies are recommended a tank size with a maximum capacity of 100 liters so that they can first familiarize themselves with the aquarium and its inhabitants.
The carbon dioxide content (CO2)
Carbon dioxide is important for the growth of aquatic plants – it is absorbed through photosynthesis and used to form oxygen. Conversely, this means that if too much CO2 is consumed, algae formation increases. A carbon dioxide system can help here, although this should be treated with caution. For example, if too much CO2 is produced at once, it can also harm plants and promote algae growth.
The filter system
The use of a filter system is essential in almost every aquarium. It removes plant residues and fish excrement from the water and treats it biologically. The rule of thumb here is: the system cannot be too big, but it can be too small – which makes it all the more important to adapt the filter to the size of the pool. When purchasing, you should pay attention to which individual properties and needs the filter must meet. This is the only way he can fulfill his task well and conscientiously.
This article contains so-called affiliate links. Further information are available here.
