Fish and other aquatic creatures

Green scurf in the aquarium: 4 reasons and 10 ways and tips on how to get rid of it


Self-purification of water in natural aquatic ecosystems occurs due to physicochemical and biological processes involving hydrobionts: living organisms and plants. The condition of the aquarium water depends on the organization of the system (maintenance mode, power and type of filter, the presence of living plants, drifts, the number of fish and food). The color of water can change under the influence of various factors. Thus, the low content of oxygen in it, which is consumed for the oxidation of organic matter, leads to an increase in the concentration of decomposition products. The water becomes cloudy, gets the smell of hydrogen sulfide. But there are cases when it becomes green. So why is the water green in the aquarium?

The reason for its turbidity is the mass reproduction of bacteria, and the water turns green usually from green microscopic euglenic algae that multiply in an aquarium. Euglena is normally always present in the aquarium, but during its reproduction begins the "flowering" of water, which can be painted in yellow-green, green colors. More often it is observed in aquariums with excessive brightness of the light source. Often, fans of ornamental fish, acquiring aquariums for the home, place them in the most convenient and "cost-effective" place - near the windows. Direct intense sunlight contributes to the active reproduction in water of green algae, which cover the glass aquarium, decorations, plants. Strong artificial lighting also contributes to the reproduction of euglena. It can be brought into the aquarium and with live food for fish from natural waters.

The first actions that are taken by novice aquarists are a complete replacement of water, cleaning plants, decorations. Such events, which seem logical at first glance, only aggravate the situation, causing bewilderment and the question of why the water is green in the aquarium, despite all efforts.

Changing water does not improve the situation. It is necessary to eliminate the causes of its “flowering” - turn off the light for a few days, shade the aquarium, located near the window. After this, the regular change of water and cleaning of the soil will allow to correct the situation, since light and nutrients only stimulate the growth of green algae. Keep the aquarium clean at all times.

You should know that the process of water self-purification will accelerate with the addition of "old" water (1/3 of the total) to the aquarium, pre-stored, rich in humic acid and a set of microorganisms that help restore a healthy environment. You should know that it is harvested from a prosperous aquarium, not overcrowded with fish, with well-growing plants.

In order not to wonder about why the water is green in the aquarium, you can run daphnias into it. At the same time, it is better to seed the fish so that they do not destroy the crustaceans.

It is also possible to purify water with the help of special preparations acquired in pet stores. Algae die off when a solution of rivanol, trypaflavin, penicillin, streptomycin is added to the aquarium.

Special diatomaceous filters and UV sterilizers help to eliminate the "blooming" of water.

In order to no longer wonder why water is turning green in an aquarium, it is necessary to achieve the necessary biological balance for its aquarium inhabitants. To support it, you need to adjust the lighting: apply curtains, screens, change the power of the lamps. Remember that it is important where the aquariums are installed. Fish will feel great with proper lighting, proper feeding, aeration and filtering.

It is useful to acquire new inhabitants of the underwater world who eat algae. These are pteregoplyhts, antsitrus, which remove plaque from glasses, mollies, Siamese seaweeds, Japanese shrimps, snails, ampouleries.

The most frequent problems with the maintenance of the aquarium

Every lover of the underwater world in the room sooner or later had to face the problems of cleanliness of the aquarium.

The most frequent problems.

  1. Turbidity of water. Water loses its transparency and becomes whitish. Most often this occurs in a new, just populated aquarium fish. This phenomenon is temporary. The development of a mass of bacteria makes the water opaque. This lasts two to three days. With proper feeding of fish and optimal temperature conditions, the next stage in the formation of the underwater world begins - the biological balance between single-celled organisms and more highly organized ones. Infusorial turbidity disappears.
  2. Ground rot. After some time, the soil may be drawn out with a dark film and periodically release bubbles. Organic matter remains rotting, which got into the ground initially either with the process of feeding the fish. To prevent this, it is better not to feed the pet than to overfeed. An additional means of combating organic matter in the soil are snails.
  3. Change the water color to green or brown. This is due to the development of algae in the water: green, blue-green or brown.
  4. Scaling on the walls. The raid is also green or brown.

These two problems are interrelated, often have common causes, and the means of eliminating them are the same. The raid on the walls - the biggest nuisance in the life of the aquarium.

Green bloom on the walls: how to get rid of?

Brown scurf caused by the development of brown algae. The reason for its formation - the lack of light in the aquarium. As in any living pond, in our closed underwater world there are all kinds of microorganisms, bacteria and algae.

Imbalance leads to the rapid development of an organism. Brown plaque is eliminated by aligning the lighting to normal. Wash the walls, change a little water and add light - and everything is ready.

The problem with kelp is solved. Most often this happens because of their replacement with green algae, as with more highly organized ones.

The most famous of the school biology course is euglena green. This alga is the main cause of the greening of water. Green algae are formed by other species, such as ethogonium and xenococcus.

These are the most common green algae, which overgrow the walls of the aquarium and stones on the ground. To deal with them is much more difficult, so consider all the ways.

  1. The main reason for the rapid development of green algae - excessive lighting. Avoid direct sunlight to the aquarium. The distance to the window should be at least 1.5 meters. Pick up lamps of artificial lighting at the rate of 0.5 W / l with a duration of not more than 8 hours per day. With a higher pH in the aquarium, green algae also grows less intensely.
  2. Regular cleaning of the walls and partial replacement of water. Take care of your underwater world and you will avoid many problems. Cleaning the walls should be done with a soft sponge, cutting with a blade is a last resort. Scratches on the glass make it possible to stay algae particles and continue to multiply. Water change should not be more than ¼ of the total volume.
  3. Biological cleaning method. This is the most desirable method. Many species of aquarium fish feed on algae. Virtually all viviparous - guppies, swordtails, petilia and molly. Karasiki, goldfish, veils, telescopes also diversify their diet with greens. Experts say that the better aquarium plants grow, the less algae reproduce. Great help in cleaning the walls and water will provide a variety of snails. They eat the remnants of the remaining food, some filter the water through themselves, thus feeding on single-celled algae. Ampularia love to gnaw algae from the glass. But, as with everything, you need to respect the measure. Daphnids and Cyclops can quickly clear the entire volume, but they themselves are tasty prey for fish.
  4. Salinization of water. In this article we look at freshwater aquariums. The sea walls do not overgrow with green algae, there are their own problems. If acidification of water is impossible due to the content of certain types of fish, you can try salting the water, no more than 1 g / l. Salt will delay the development of green algae in water.
  5. Chemical method. Antibiotics are applicable in the fight against bacteria and lower algae, if the problem has gone too far and other methods do not help. It is possible to treat an aquarium with Riboflavin, Trypaflavinum, Rivanol (0.1 g per 100 l). But when using these substances, snails and some aquarium plants with delicate green leaves are affected. Kabomba and rogolotnik drop foliage immediately after applying these drugs. Streptomycin and Penicillin are less rigid. Plants and fish will not be affected. The applied dose of Streptomycin - 0.3 mg / l for 48 hours, then the water should be replaced. The safest chemical to disinfect an aquarium is 3% hydrogen peroxide. Concentration from 2 to 6 mg / l with enhanced aeration. Water change is not required.

Biological balance - a pledge of the purity of your aquarium

The easiest way to achieve a clean aquarium is to organize it right from the start.

In a properly organized aquarium, biological balance is established, and the water in it can not be changed for years.

A few tips on how to start an aquarium device.

  1. The greater the volume, the easier it is to establish a biocenosis in it. Aquariums from 10 liters are generally regarded as temporary - for jigging fish for the duration of sanitary work or for the time of spawning. The ideal aquarium is an aquarium of at least 100 liters. Only in such a water space can life organize itself.
  2. The population of the aquarium fish should be at the rate of 1 fish of an average size per 5 liters of water, preferably a little more liquid. Should take into account the planting. Plants absorb the waste products of fish and snails from water, saturate the water with oxygen by processing carbon dioxide during photosynthesis. But at night, the plants themselves consume oxygen, and the process of photosynthesis stops at this time. Therefore, an overabundance of plants can play a cruel joke with an inexperienced aquarist, although this is rare. An excessive number of snails can turn from a detachment of cleaners into a crowd of pollutants, it is necessary to thin out their population in a timely manner.
  3. Acquire fish, plants and snails preferably in specialized stores or from experienced breeders. The risk of infection from a natural reservoir is too great. This also applies to the infection of the aquarium by the euglene during the summer period, when it multiplies intensively in ponds and lakes.
  4. Feeding fish should be very moderate. Dry food should be eaten in 10-15 minutes. Preference, of course, fresh live food. For most aquarium fish, it is not particularly difficult to post 3-4 days. If you are going to be away at home, do not pour food for the future.
  5. Illumination. You should install the aquarium so that it does not fall into direct sunlight, but the illumination was sufficient. A distance of 1.5 m from the window would be ideal. Solar lighting is best organized in the morning, and the duration of lighting 8-10 hours per day is sufficient. The lack of sunlight can be compensated by artificial lighting.

The established biological balance in an aquarium is characterized by the transparency of the water and the natural greenness of the plants. The color of the correct water, if you dial a glass from the aquarium, is yellowish. This is the so-called Fish condition water.

The water became alive, the biocenosis was established. After about a week of functioning of the indoor underwater world, this should happen. If not, you need to analyze the errors, but you should not panic. Nature is wise, you just do not interfere with it.

Euglena Green

The name of these single-celled algae speaks for itself and is perfectly familiar to people who have long been breeding ornamental fish. Euglena forms the thinnest film on the water surface and is an important link in the food chain.

Under poor lighting, the green body of euglene becomes discolored: the alga visibly fades or loses its color completely.. Mass reproduction, leading to increased flowering of water, occurs when:

  • intense light
  • the excess in water organic components
  • failure of aquarium filters.

Euglena bloom can be very stormy: just yesterday the water was absolutely transparent, and today it has acquired a dull green shade.

Other factors

The provocateurs of greening aquarium water are also considered:

  • unnecessarily frequent maintenance of the tank (water purification, renewal / aeration),
  • poor maintenance of the aquarium (lack of a compressor, insufficient aeration, rotten water),
  • high water temperature
  • a huge number of planted plants
  • accumulation of chemicals in water (organic substances),
  • the wrong lighting mode (more than 10-12 hours per day) or direct sunlight directed at the aquarium.

Important! Beginners lovers of ornamental fish make another common mistake, feeding them without taking into account the natural needs. Fish do not have time to completely eat food and it sinks to the bottom, where it rots, contributing to the greening of water.

Natural cleansing

Run into the aquarium so many live daphnias that the fish could not eat them immediately. These plankton crustaceans will easily cope with the surplus of unicellular algae, bred in the "fish house". Settle in it "tenants", whose main food is considered to be algae: fish (catfish, mollies, placium) and snails.

Find a small pemphigus and a robepole (aquarium), which, due to their accelerated growth, absorb an excess of nitrogen accumulated in water (a flowering catalyst). So, the horn leaf for a week is capable of stretching 1.5 meters. Preliminarily remove humus from the bottom, replace 1/2 of the water and only then place the plants in the aquarium.

Mechanical cleaning

First, check the operation of the aquarium equipment to make sure there are no problems. It may be worthwhile to get additional devices for water clarification, such as:

  • UV sterilizer that regulates algae reproduction by directed ultraviolet rays,
  • diatomaceous filter - due to the special filtering composition, it retains contaminants and weighted elements, measured in microns.

Mechanical cleaning methods can be combined / intermixed with chemical methods.

Chemical cleansing

The operation of the aquarium filter will become more productive if you put activated carbon in it (in granules). In the process of getting rid of green water, the filter itself is cleaned 1-2 times a week.

It is interesting! Another tried remedy is powdered (crushed) streptomycin diluted in water. Per liter of aquarium water enough 3 ml of solution. This dosage does not affect the fish, but it fights well with the growth of unicellular algae.

It does not hurt to acquire a coagulant "Hyacinth", created for the purification of drinking water, but extremely useful in aquarism. On the manufacturer's website, it costs 55 hryvnia, which corresponds to 117 Russian rubles. The drug is tested in action. It turned out that its active formula is capable of neutralizing both organic and inorganic harmful impurities.

What to do with the inhabitants of the aquarium

Please note that the deterioration of the aquatic balance is bad for the health of all aquarium guests.

Manipulations for water purification should be accompanied by parallel activities:

  • if the fish are healthy, move them temporarily to other containers with a similar composition of water,
  • place the plants in temporary containers, stirring methylene blue in water (dosage according to the instructions),
  • if necessary, replace the old soil with a new one (pre-treated for parasites),
  • Pour out the old water, fill the aquarium with water with the addition of baking soda (1-2 tsp.) and leave for a day,
  • Scald / boil all artificial decorations, including grottoes, snags and shells.

If the fight against greening is not radical and the fish remain in the aquarium, only a third of the water is usually changed to fresh.

Prevention and recommendations

There are simple preventive measures that will help eliminate the possible flowering of water.

For him, you need to choose the right position - away from the sheer sunlight or window sill, where they can get (leaving about a meter and a half).

When installing the aquarium try to lay the ground with a slight inclination towards the front wall. So it will be more convenient to clean the soil and carry out general cleaning in the aquarium. Systematically clean the bottom of debris, especially rotten leaves, and make a partial replacement of water.

Installing a new aquarium, increase the light flux smoothly, in the first days, limiting 4 hours per day. Gradually bring the length of daylight hours to 10-12 hours.

Important! Water lighting should be only artificial, preferably fluorescent lamps: per liter usually accounts for 0.5 watts.

Do not forget to cover the aquarium and turn off the lights in time. Healthy aquatic vegetation does not suffer from a lack of light for at least a week. Эти несложные действия предупредят нерегулируемое цветение, сохранив деньги, которые вы израсходуете на спасение воды.

Уход за аквариумом

Аквариумисты со стажем знают, что размножение эвглены зеленой может принять систематический характер. That is why it is important to set up the correct nitrogen cycle when you first start the aquarium.

Important! It is recommended to use water from the former aquarium (if it was) and a used filter cartridge. Reduced light consumption will also help to adjust the nitrogen cycle - approximately 2 hours a day for a month.

Periodically it is necessary to monitor the operation of all aquarium devices. If the greening of the water is caused by excessive feeding of fish, read the special literature to know how much food your pet needs.

Causes of water greening

The water in the aquarium turns green due to an excessive amount of microscopic algae. They, like the higher plants, contain a pigment of green color - chlorophyll. Where do algae come from? Depending on the type of spawned algae, the water may be dark or light green.

Aquarium is a small ecosystem. Until biological equilibrium is established in it, it is, in essence, just a can of water. Only some time after filling with soil, planting plants and launching fish, a bio balance is established - the optimum ratio of hydrobionts, bacteria and substances contained in water.

Hydrobionts are marine and freshwater organisms that constantly inhabit the aquatic environment.

In general, algae fall into the aquarium with fish, higher plants, snails. Avoid getting hit is almost impossible, but usually their presence does not interfere. If, from the very beginning, the aquarium was equipped incorrectly, the aquarist made a mistake in its content, or for some other reason there was a malfunction in the water system, then problems are inevitable. The rapid reproduction of algae, which causes greening, which is also called “water bloom,” can be caused by the following reasons:

  • Excessive light generated when the aquarium is at the window and the sun's rays fall on it, or if the power of the lamps is too strong. It must be remembered that algae, like plants, use the energy of light in the production of nutrients for their growth and development. With too much light, an excess of energy is formed, respectively, the nutrition of algae increases and they begin to grow more intensively, filling the aquarium. This problem can also occur when the day is too long when the lamps are lit 10–12 hours.
  • Unsuitable range of lighting lamps. Each light source has its own intensity and length of the emitted waves. Their various combinations are good for some plants and not suitable for others. If lamps with a spectrum optimal for algae are randomly selected, this will be an incentive for their growth.
  • Overfeeding fish. As a result of enhanced feeding, the amount of fish waste increases, which, in turn, increases the water content of ammonia and its derivatives, nitrites and nitrates. Plants use nitrates as nutrients, and algae, respectively, too. The result is the same as with excessive light, especially if there are few plants planted and a filter that is not too powerful is used.
  • Overpopulation of aquarium. Too dense planting of fish (their large number or the content of large species in a small litrage) also leads to an excess of nitrites and nitrates, and, consequently, to the growth of algae.
  • A small number of plants or their complete absence. Nutrients formed from fish excrement, as well as light, in this case, simply cannot be absorbed, and algae occupy a free niche.
  • Wrong care for the aquarium. For example, too often washing the filter violates the biobalance: nitrifying bacteria are destroyed. And rare water changes contribute to increasing the concentration of nitrites and nitrates above the norm.
  • Other biological imbalances. Since the artificial ecosystem is very sensitive to various changes, any abrupt changes in the aquarium, for example, the death of fish or the sharing of new inhabitants can be included here. There may also be an excess or deficiency of micro or macro elements in the water.

The above reasons can cause not only the greening of the aquarium. Water can remain pure, but green, blue-green or brown algae growing on glasses, soil and scenery will go to growth. The reasons for their appearance are the same. When the glass is overgrown with green bloom, it may seem that the water is green

If the aquarium glass is heavily overgrown with green algae, the water may also appear green. You can check the color by typing a little bit of it in a transparent vessel or by cleaning the glass on the inside.

Beginner aquarists sometimes confuse the flowering of water with its clouding. Whitish cloudiness occurs due to a bacterial outbreak - a sharp increase in the number of bacteria, not algae. It is much more dangerous for fish and is treated with frequent water changes, as well as measures to normalize the biobalance. Water clouding or white suspension in an aquarium is a symptom of a bacterial outbreak, much more dangerous than water blooming.

What is dangerous green water

If the water has blossomed in the aquarium, you should not be afraid. For fish microscopic algae do not harm. However, they take the nutrients from the plants, which ultimately violates the biobalance even more. Changes in the composition of water and inhibition of plants due to competition with algae will lead to a reduced oxygen content in the water, which ultimately will not have the best effect on the inhabitants of the aquarium.

And the main reason for wanting to get rid of water greening is an unaesthetic type of aquarium. I want to admire the home corner of the underwater world, clearly see the fish and plants, and green algae this strongly interfere.

Ways to troubleshoot the problem

Many aquarists are faced with the problem of water blooming, so today there are a lot of ways to eliminate it.

Regardless of the method chosen, after the water begins to be cleared of greenery, you need to start making changes, 10% of water every day. Dead algae will begin to decompose, saturating the water with organic matter and, consequently, increasing the level of harmful substances.

Natural methods

The most interesting, of course, methods using other plants or animals. Living creatures are “embedded” in the aquarium ecosystem and do not harm it, unlike chemical methods. Choosing the right lighting can also be attributed to this category.

  • Daphnia settlement. In the aquarium, you can settle the microscopic crustaceans - daphnia, which feed on algae. They will quickly clear water of greens. You need to run a very large number of Daphnia, so that the fish do not eat them immediately. This option is not very suitable for an overpopulated aquarium: there is little oxygen in it and daphnids will quickly die. In this case, you can additionally enable aeration. Daphnia microscopic crustaceans are a nutritious food for fish, and can also save aquarium water from blooming
  • Willow Some aquarists recommend this method: you need to cut the branch, wash it well and put it in the aquarium. After some time, it will take roots and the water will begin to be cleared of green algae. On the 2-3rd day of lightening the water, willow needs to be removed, as it will begin to inhibit aquarium plants, absorbing all the nutrients.
  • Blackout aquarium. You can try to completely turn off the light in the aquarium for 2-3 days. It is also necessary to close its walls with cardboard or cloth, if sunlight gets on them. This method does not always help, since during prolonged darkening, higher plants suffer, and there are not enough algae for several days to die. When the lights are off, it is advisable to increase aeration, as the plants in the dark do not emit oxygen into the water and fish can suffocate.
  • UV sterilizer. Installation of an aquarium ultraviolet sterilizer is considered the most effective method. It helps to cope not only with unicellular algae, but also with many bacteria and protozoa, dangerous for fish. It should be turned on when the water blooms for 2–4 days, preferably around the clock.

In the fight against algal blooms and algae, proper lighting is of utmost importance. The author of the article for his first 72-liter aquarium chose two fluorescent lamps with a total capacity of 40 watts. They turned out to be too strong and contributed to the rapid growth of blue-green algae, and then a green touch on the glass. The situation improved when the lighting was reduced by half.


In the fight against unicellular algae, causing greening of water, you can use chemicals. Various companies have developed special tools, these include:

  • Dajana Algicid. Regulates and inhibits the reproduction of algae in the aquarium.
  • Aquarium Pharmaceuticals Algae Fix. Removes any algae, including “black beard”.
  • Tetra Pond Algo Rem. Means to combat green algae, turning them into clumps that are convenient to catch a net.
  • Tropical Algin. The drug to combat the flowering of water in ponds, which is sometimes used for aquariums.

All of the above means should be applied strictly according to the instructions on the package, as a violation of the dosage and other rules of use can cause harm to fish and aquarium plants. Algaecides - means to combat algae, they help to get rid of uninvited guests in an aquarium or pond without much difficulty

One of the reasons why aquarists often do not want to use chemicals is a possible danger to aquatic organisms, because even if used correctly, a low-quality tool can lead to poisoning of their favorite fish.

Important! As a rule, preparations for algae control have a negative effect on invertebrates. You need to be careful with them if there are shrimps, crayfish, crabs, snails in the aquarium.

Mechanical cleaning

An interesting way to deal with water blooming, rather effective in response to feedback is to use microfiber or padding polyester in an aquarium filter.

  1. Buy a microfiber cloth (sold in hardware stores) or sintepon.
  2. Rinse well the purchased material.
  3. To wind a rag on a rod of the internal filter, at the same time it is not necessary to dress a glass, it is possible to fix fabric with an elastic band. If the design does not allow, you can put the fabric in the filter cup.
  4. Rag should be washed as it is contaminated, 1-3 times per day.
  5. Filter the aquarium water in this way until it becomes clear.

It is better, just in case, to buy several microfiber cloths, since, according to reviews of aquarists, their varieties differ in their effectiveness. According to reviews, the use of padding polyester or microfiber in the filter allows you to save water not only from the green, but also from turbidity


It is better to prevent the water from becoming green than to fight it for a long time and unsuccessfully. It is not always possible to eliminate all risk factors, but at least it is necessary to minimize them. To do this, follow the general rules of care for the aquarium:

  • weekly replace 10–25% of the aquarium water with fresh water that is surely settled or with the addition of special air conditioners,
  • remove the rotten parts of the plant from the aquarium in time
  • do not overfeed fish: feed them no more than two or three a day in such a quantity of food that is eaten in 5 minutes,
  • Avoid overcrowding the aquarium
  • New decorations, stones, driftwood, soil is recommended to boil before diving into the aquarium,
  • New aquarium plants should be washed well before planting with warm water,
  • select the lamp power and day length optimal for the plants living in the aquarium
  • close the aquarium from the sun's rays.

Aquarist, it is desirable to have special tests to control the parameters of water. With their help, you can quickly identify critical imbalances. The most important tests are nitrate, nitrite, ammonia / ammonium, Ph, GH, Kh.

There are many ways to eliminate the greening of water, but it is not known which one would be suitable in a particular case. It is necessary to focus primarily on the availability of the method and its safety for aquatic inhabitants. The main thing, using methods to combat water bloom, in parallel to normalize the balance in the aquarium. Then getting rid of green algae will be easier and they will not return again.