Connect with us

Aquarium – How to fight (get rid) of plaque


Animal diseases

Aquarium – How to fight (get rid) of plaque

how to fight (get rid) of plaque, why it appears, reasons – Brown algae belong to the group Diatoms or Diatoms. Although in the Diatoms group there is the “Brown algae” species, only marine plants are included there (for example, sea palm, kelp – sea kale). And in relation to aquarium algae, brown is only a color. They are also called brown, red or yellow.

The Diatom trait is considered the ability to absorb and process any organic matter. Therefore, brown algae so rapidly developing in water. Most often, the main reason for the appearance of Diatoms is an excess of ammonia or nitrogenous compounds in the water that harm the underwater inhabitants.

Brown algae is a problem that many aquarists have encountered, not just beginners. The formation of diatoms in the aquarium indicates a violation of the biosystem of the reservoir with underwater inhabitants.

A brown coating appears in the aquarium suddenly and affects plants, stones and walls. If brown algae in the aquarium can not be fought, then in a few days they affect the entire tank and lead to the death of vegetation. And to get rid of you need a couple of weeks or months. Therefore, it is better to know in advance about the causes and methods of controlling brown algae in the aquarium.

Reasons for the appearance

You can learn about the appearance of Diatom in the reservoir by the first and main symptom – a brown or yellow coating formed on the vegetation. The first symptoms are the formation of light dust or turbidity in the water, which is barely noticeable. At the initial stage, plaque is easily erased and raises dust if it is shaken off. If Diatoms are not noticed, then over time the layers grow on each other. The color changes from brown to black. The top layer is also easy to clean, but older layers are more difficult to remove. The transparency of the glass of the aquarium is greatly reduced.


There are several reasons for the appearance of brown plaque in the aquarium, and they depend not only on care, but also on the age of the microflora of the aquarium.

In a young tank, launched less than 3-4 months ago, the appearance of brown algae in an aquarium is common. In this container, living plants have only recently been planted, have not yet had time to take root and begin to absorb substances from the water. At this time, nothing prevents Diatoms from actively reproducing.

In a young aquarium, the correct nitrogen cycle is also not established. Food debris and waste products of fish begin to rot and decompose much faster. Such an environment is favorable for the reproduction of brown Diatoms.

Even more often, in a young reservoir, the acidity of the water is low, usually alkaline or neutral water. With such indicators of water, plants and microorganisms are not able to absorb many compounds. If the acidity is above 7pH, then the water will have a high concentration of ammonia, which diatoms feed on. And at an acidity below 7 pH, the water contains enough ammonia, which is used by underwater plants.

If brown deposits on plants and walls appear in a well-functioning and long-running aquarium, then the main reason is the accumulation of organic substances in the soil and water, which turn into ammonia.

Incorrect filter operation also leads to brown plaque. If the filter is clogged or completely absent, then the water is not cleaned. This leads to the accumulation of organic substances.

Fertilizing is also not always beneficial. Fertilizers are the source of ammonia that algae needs. If you make a lot of fertilizers, then the plants do not have time to absorb them. In a young aquarium, additional fertilizers are not required, except for potassium in small doses.

Low water temperature of 16-21 degrees accelerates the development of brown algae.

The main reason for the appearance of algae is improper care and a rare cleansing of the aquarium. If you do not change part of the water weekly and do not wash the aquarium every few weeks, then particles of food remain on the walls and in the ground, which subsequently decomposes.

If a brown coating appears on the plants, then a possible cause is a high concentration of iodine. Iodine is used to treat certain fish diseases. If the treatment took place in a common aquarium and was repeated, then iodine accumulates in water and causes the multiplication of Diatoms. Iodine also slows down the development of plants, upsetting the biological balance.

cause algae improper care
cause algae improper care

Diatom settles in the aquarium using table salt to treat fish and disinfect water. Sodium is included in the diet of Diatoms, and also helps them absorb other mineral residues contained in the water. And since sodium is contained in salt, its excessive concentration in water helps to develop algae and interferes with getting rid of Diatoms.

The aquarium is covered with a brown coating even with a sharp change in the regime of care. This happens when transferring the aquarium to a new owner. Even if the former owner poorly looked after the fish, rarely washed the aquarium, then you can not immediately change the usual biological environment. Change the care gradually, otherwise a sharp change will cause a surge in the development of algae.


Over 150 years after the discovery of the Diatom species, more than 300 genera were officially discovered, which included 5,000 species. But it is believed that their number, including as yet unexplored, is 10,000–20,000 species. The whole view is divided into two classes: centric and pennate Diatoms.

All species are divided according to 4 characteristics:

  • colony type;
  • internal structure of cells;
  • shell structure;
  • amount and form of chloroplasts contained.

The most common species in the natural environment are Navikula, Pinnularia and Zimbella.

species of diatoms
species of diatoms


Navikula – a detachment of unicellular algae, belongs to the diatom department. It makes up a significant part of underwater plankton. Discovered by Ernst Haeckel.

This species of algae is the most numerous, it includes more than 10,000 species. Under a microscope, the Navikula cell resembles an oval stretched to the edges, therefore in Latin it means “Boat”. The habitat is heterogeneous, Navikula lives in the soil, settles on the rocks and is located in rivers, lakes and seas.

They feed on photosynthesis of solar energy. For movement on the surface, a mucus secret is secreted, which helps to move.

Active in spring and summer; at the same time they often end up in aquariums. In vivo they make up a significant part of the food chain.


Pinnularia is a unicellular alga living on the bottoms of water bodies. The cell consists of 2 connected halves, in the middle of which the nucleus is located in the protoplasmic bridge. Propagated by cell division every 5 days, during division, part of the carapace remains in the separated cell, and the second in the mother. The missing part of the shell grows back after a couple of hours.

Actively moves among the silt at the bottom, often gets into home aquariums. High activity is shown in the warm summer-autumn time.


Cymbella is an alga from the genus Diatoms, having a diverse species composition. Cells in the form of elongated roundness, outwardly resemble an oval, ellipse. Mostly active in the summer. For a long time, cymbella are able to fix in one place and remain motionless. The rest of the time they move along the bottom in search of food.

A significant part of the diet of underwater insect larvae, which are subsequently eaten by fish, is cymbella.

Methods of struggle

You need to start fighting Diatoms at the first sign of their appearance, otherwise then getting rid of brown algae in the aquarium will be too dreary. Among the cleaning methods, lighting, chemical, physical and biological methods and maintaining the cleanliness of the aquarium are considered the most effective.

how to deal with diatoms
how to deal with diatoms

Maintaining optimal conditions

The correct regime of the day, temperature and water parameters, a balanced diet will provide protection from pests. But if algae still appeared, then proper care will also help to remove them. In most cases, the cause of plaque will happen if the aquarium is rarely cleaned or of poor quality and the water changes. Therefore, now weekly replace part of the water, about 1/3 or 1/4 of the share. With severe contamination of the aquarium, replacement is more often. Water should remain clean and clear at all times.

If before that the aquarium had a low temperature of 18–22 degrees, then increase it by several degrees (provided that this does not harm the fish). A temperature of 23-24 degrees will be enough.

The accumulation of organic matter is the main cause of red plaque, so adjust the feeding of the inhabitants. All food should be eaten within 15 minutes after immersion in water. If the fish leave part of the food, then cut back on portions, and remove excess food from the water. After all, food particles settle to the bottom, clog into the ground and the process of decay and decomposition begins.

The speed of contamination of the aquarium by the waste that algae feeds also depends on the number of pets. With a large number of fish, water should be cleaned and siphoned more often than with a small flock.

Check the quality of tap water. Sometimes it has a high phosphorus content, which also causes the appearance of plaque.

brown algae on stones in an aquarium
brown algae on stones in an aquarium


The cause of the appearance of algae is also the lighting of the aquarium, which is too long or, conversely, short daylight hours. This increases the speed of chemical reactions in the aquarium and algae will begin to multiply rapidly. Long daylight hours in a young aquarium are especially dangerous.

To get rid of plaque, reduce the duration of daylight hours to 6 hours a day for 3 days. After that, return to the normal mode of the day by increasing the lighting to 10 hours a day. Continuous daylight hours will have a beneficial effect on the cleanliness of the aquarium and the health of the fish.

aquarium lighting
aquarium lighting

Do not use lamps that have expired or are already running out. But you cannot change all the lighting at once. Change each lamp with an interval of a couple of weeks, so that the inhabitants have time to get used to. A sharp change in lighting will cause a jump in the reproduction of algae.

Lamps that are not intended to illuminate the aquarium are also capable of causing a brown coating on stones and plants. With a power of about 1 W / liter, they are suitable for lighting and disposal.

Prolonged exposure to direct sunlight sometimes also causes algae to develop intensively. It is advisable that bright sunlight does not illuminate the aquarium for more than a couple of hours a day.

Chemical methods

Use chemistry in the fight against algae in the very last case, when the other methods did not help, because any chemical intervention harms the fish and changes the bio-balance in the aquarium. For chemical cleansing, preparations are suitable:

  • penicillin;
  • bicillin-5;
  • Algetten tablets.

These drugs quickly clean the aquarium, but the causes of the algae have not been removed, so after a while they may return.

Mechanical cleansing

Many young aquariums go through the fight against Diatoms. But in a short time after the creation of microflora in the water, algae disappear. In this case, you only need mechanical cleaning of the plaque from the walls of the aquarium. For this, you will not need hard objects, like brushes. Young algae are easily removed even by fingers, so wiping the surface with a rag will be enough.

If the brown plaque has already managed to get stronger and is difficult to separate from the glasses, then use sponges, scrapers, soft small brushes.

Plaque on plants should be removed with extreme caution. It is cleaned with hands or soft tissues. But do not use sponges or foam rubber. With prolonged lesions, the leaves decompose and it becomes impossible to remove plaque from them. It is better to dig up such plants, and then either discard or cut off the diseased leaves and leave the rhizome, transplanted into a separate tank.

It is easy to mechanically remove young deposits on soil and stones by siphoning the substrate or simply under running water. Rinse from dirt need aeration and filtering equipment.

Mechanical removal of brown algae

Biological fight

Underwater animals and plants help get rid of algae. Algae are included in the diet of some fish and other inhabitants, and living plants establish a gas exchange.

Species that can fight algae:


Diatom does not harm the underwater inhabitants of the aquarium and does not affect them in any way. But this plaque creates a favorable environment for the development of more complex algae. Red, green algae interfere with the normal development of the aquarium and spoil the appearance.

A more serious problem would be the appearance of a black beard diatom, belonging to the Red Algae group. This dark alga with hairy leaves settles on the leaves of slow-growing plants and feeds on the finished organic matter of the leaves. Another black beard closes the access of light and stops the photosynthesis of leaves. The leaf gradually dies, and the beard moves to another place.

brown algae damage
brown algae damage

Brown plaque that appears on plants is dangerous, because it prevents the exchange of gases with the environment and the process of photosynthesis. This leads to the death of the plant. The leaves will gradually decompose and infect nearby plants.

Preventative measures

Prevention is always the best way to maintain a healthy aquarium. There are several rules and tips that will protect the aquarium from most Diatoms and other unpleasant microorganisms:

  • If possible, get lamps with red spectral light.
  • Maintain a constant water temperature.
  • Replace part of the water volume weekly.
  • Keep your aquarium clean.
  • Equip the aquarium with filtration and aeration systems.
  • Plant live plants.
  • Watch the water parameters: hardness, acidity, the amount of iodine, silicates, nitrates.
  • Place objects made of zinc or copper metals at the bottom.
  • Once every one to two months, carry out a general cleaning of the aquarium, removing and cleaning all decor items and equipment.

Following the advice and maintaining the standard of living of pets, it is not difficult to get rid of Diatoms, and after a couple of weeks your aquarium will become clean again.

Continue Reading
You may also like...
Click to comment

Leave a Reply

Your email address will not be published. Required fields are marked *

More in Animal diseases



To Top