Types of algae in freshwater aquarium

Types of algae in freshwater aquarium

Algae grows in, salt water and freshwater aquariums, which means that the aquarium is live. Aquascapers differentiate between the plants that live in an aquarium and algae.

However, it is the aquarium plants that we keep alive, and the algae are unwanted and unloved guests since they only spoil the appearance of the aquarium. Let’s just say that algae growth for the fishkeeper is just a sign that something is wrong in the aquarium.

The issue of algae outbreaks in the aquarium periodically torments both beginners and the pros of aquarium craft. And all why? Because these unwanted guests can appear both “in a young” and “in an old” reservoir.
An experienced fishkeeper will immediately notice unwanted algae and, knowing roughly its name or genus, will quickly neutralize it, preventing an outbreak. But beginners have a hard time!

The situation is aggravated by a variety of information on the issue of algae control. Some say: keep the aquarium in the dark, others, on the contrary, increase daylight hours! Some say: this is an overdose of fertilizers in the aquarium, while others, on the contrary, is that you have little macro fertilizers, etc.
Let’s figure out what’s wrong with the aquarium ?! How to deal with it! Let’s debunk the legends and myths about algae.

There are many types of algae in freshwater aquarium algae but what are they? Many beginners call aquarium plants algae, and vice versa, plants call algae! This is a fundamental misunderstanding of the essence of plant nature.

Aquarium plants are the highest of the plant kingdom. In the aquarium, these are the same plants as in the field or on the lawn near the house. This is a biological kingdom, one of the main groups of multicellular organisms, including, but not limited to, mosses, ferns, horsetails, moss, etc.

Algae are inferior. A heterogeneous ecological group of predominantly phototrophic unicellular, colonial or multicellular organisms, usually living in an aquatic environment, systematically representing a collection of many departments. Entering into symbiosis with fungi, these organisms in the course of evolution have formed completely new organisms – lichens.

Having differentiated these two concepts, we have decided with whom specifically we need to fight. Our aquarium enemy – algae, the lowest of the plant world!

Types of algae in freshwater aquarium

All aquariums contain algae, on sand and gravel, rocks and plants, walls, and equipment. They are quite natural and are part of the normal balance if they do not grow rapidly.

All that is required of a balanced aquarium is clear, well-mixed water and clean glasses. I even advise not to clean all the walls of the aquarium, leaving the back covered with fouling.

I have noticed that when algae are left to grow on the back wall or on rocks, it absorbs nitrates and other debris, thereby reducing the potential for algae to grow on the front and sidewalls of the aquarium.

Also on overgrown aquarium glass, some fish will feed on algae and microorganisms, such as all types of chain mail catfish.

Green algae in the aquarium or Xenococcus

Found in most aquariums as green dots or green sheeting. These algae love a lot of light. Green algae only grow if the amount of light and nitrate exceeds the level that higher plants can absorb.

In densely planted aquariums, green algae develop extremely poorly, as the higher plants consume nutrients and absorb the light necessary for the vigorous growth of green algae.

Green algae in the aquarium or Xenococcus

Without condemning the use of plastic plants in an aquarium, I would like to note that live plants look the best and create conditions for the normal development of the entire biosystem.

However, they can grow en masse in aquariums with CO2 systems, due to fluctuations in carbon dioxide levels throughout the day. An outbreak of green algae growth can occur suddenly, especially when the level of phosphate and nitrate in the water is high.

They usually appear as green dots covering the glass surface and the bottom of the aquarium. The recommended remedies are to reduce the amount of light and the length of daylight hours, and mechanical cleaning – with special brushes or a blade.

Mollies and catfish, such as ancistrus, eat green algae very well, and I keep several specifically for this purpose. The Neritina snail also copes well with xenococcus and other algae.

Black beard

The appearance of a black beard in the aquarium is a sign that the amount of waste has increased greatly because organic residues serve as food for it. It is these algae that most often grow on the walls of the aquarium and the plants in the aquarium, in the form of a thick and disgusting black carpet. How to deal with a black beard?

Black beard

The main method of struggle with it is to reduce the level of organic matter. Soil cleaning, water changes, and filtration seriously slow down and reduce the growth of black beard. To do this, you need to remove organic residues from the soil – slightly siphon the surface of the soil.

Also, a black beard likes to settle in places with a good flow, these are filter tubes, filter surfaces, etc. The current gives the beard abundant nourishment, organic matter settles on its surface.

It is recommended to reduce strong currents in the aquarium. To reduce the number of nutrients in the water, in addition to harvesting, you can have various fast-growing plant species – waterweeds, najas.

How to deal with a black beard in an aquarium? Recently, a new remedy for combating beard and red algae has appeared – Cidex. It was originally used (and is used) in medicine for disinfection.

Who came up with the idea of ​​using cidex against a black beard, apparently, will remain unknown. But the fact is that cidex works, moreover, against both black beard and red algae.

Cidex is poured once a day, in the morning. The initial dose is 10-15 milliliters per 100 liters of water. Gradually, you can increase to 25-30 milliliters (be careful, at 30 ml Platydoras died!).

The red algae begin to die at 15-20 milliliters. They write that it does not completely kill it, but this is not so. You just need to add cidex for another two weeks after the red algae disappear completely.

There is an experience of complete cleansing of aquariums from it. At small doses (up to 20 ml), no negative effect on fish was noticed, however, some plants – Ceratophyllum, Vallisneria, Cryptocoryne, and many other types of algae in freshwater aquarium do not like cidex and may die.

In any case – this mention of the drug is for informational purposes only, be sure to read the profile forums before use. This drug is not safe!

Brown algae in the aquarium

Brown algae grow quickly if there is too little light in the aquarium. They look like brown patches covering everything in the aquarium. Usually, plants that love light are in poor condition or disappear.

Brown algae in the aquarium

Plants that tolerate shading well, such as Java moss, dwarf anubias, and other types of anubias, can be covered with a brown film, and the tough leaves of anubias can be rubbed to get rid of the brown algae.

Again, aquarium cleaners, bristlenose pleco, or otocinclus are helpful. But the simplest solution is to increase the intensity and duration of daylight hours. Usually, brown algae will quickly disappear, as soon as the lighting is in order.

Brown algae very often form in young aquariums with unstable balance (less than ~ 3 months old), with the wrong lamp spectrum and with too long daylight hours.

An even greater increase in daylight hours can lead to even worse consequences.

Red algae in the aquarium
A frequent visitor to new aquariums with unsettled nitrogen cycles. By nature, it is close to a black beard and therefore the methods of dealing with it are similar. Reducing nitrate levels by cleaning the soil, replacing water, and filtering with a powerful filter.

First, red algae is many times more tenacious than a black beard. Even a month in complete darkness does not kill her. It is tough, strong, and firmly attached to any surface.

Secondly, no one eats it, except for 1-2 species of snails.

Thirdly, the reason for the appearance. The red algae is usually brought in from other aquariums.


Or diatoms (lat. Diatomeae) are a large group of unicellular algae. Mostly unicellular, although there are also forms in the form of colonies. The main difference between diatoms is that they have a shell made of silicon dioxide.

Watch the video from this mark to get to know how diatoms look:

Diatoms. Part 1: Introduction and collection of diatoms
This species is very diverse, some are quite beautiful but mostly look like two asymmetrical sides with a clear separation between them.

Fossilized remains indicate that diatoms appeared in the early Jurassic period. More than 10,000 different species are now found.

In the aquarium, they look like brown algae, which cover all internal surfaces with a continuous film. Usually, appear in a new aquarium or when there is a lack of light.

You can get rid of them as well as brown ones, by increasing the number and length of daylight hours. It is also worth using an internal filter with a carbon filter to remove silicates from water.

Blue-green algae in the aquarium

Blue-green algae are colonies of bacteria, and this is how they differ from other types of algae in freshwater aquarium. They look like a green, slippery film covering the soil and plants in the aquarium. They rarely appear in the aquarium, and, as a rule, in those that are poorly looked after.

Blue-green algae in the aquarium

Like all bacteria, they secrete substances that have a detrimental effect on plants and fish in the aquarium, so they must be carefully controlled. How to deal with blue-green algae in an aquarium?

As a rule, the antibiotic bicillin, or other types of antibiotics, are used in the fight, but you need to work very carefully with it, you can irreversibly affect all the inhabitants of the aquarium. Better to try to balance the aquarium by doing a large water change and cleaning.

Green water in the aquarium or blooming water

Green water in the aquarium is obtained due to the rapid reproduction of a single-celled alga – green euglena. It manifests itself as a cloudy water to a completely green color. The water loses its transparency, the balance in the aquarium is disturbed, the fish suffer.

Green water in the aquarium or blooming water

As a rule, water bloom occurs in spring, with an increase in the amount of light, and water bloom in natural reservoirs from which we obtain water. To combat water bloom, you need to reduce the amount of lighting in the aquarium to a minimum, it is better not to light at all for a while.

The most effective method is a UV lamp installed in an external filter.

A very effective way to combat water bloom is to make a change and completely shade the aquarium for 3-4 days (for example, cover it with a blanket). Plants will survive this. Fish too. But the water usually stops blooming. After that, make a substitution.

Filamentous algae

The filament in the aquarium consists of several types – Oedogonium, Spirogyra, Cladophora, Rhizoclonium. All of them are united by their appearance – similar to a thin thread, green balls. It is a filamentous green algae. How to deal with floss in an aquarium?

Filamentous algae

An effective method of control is the use of algicides – agents that help to fight algae in the aquarium, they can be purchased at pet stores. The simplest and most affordable method is manual removal.

As a rule, the threads are quite fragile and easily detach from the surface. Also, some types of filamentous algae shrimp are happy to eat, for example, a flock of Amano shrimps can easily cleanse even a large aquarium of filamentous algae.

Its appearance and growth depend on the nutrient content of the water. This is usually due to the fact that either too much fertilizer has been poured into the aquarium, or there is a substrate soil in the aquarium, it releases nutrients and there is no one to absorb them. In such cases, substitutions and fast-growing plants (najas and elodea, ceratophyllum ) help

What to do to inhibit growth on any types of algae in freshwater aquarium

  • An aquarium with a large number of aquarium plants, algae will still be in it, but they will not develop rapidly.
  • Good aeration of water – increased oxygen content inhibits algae growth.
  • Filtration and stirring of water to remove organic residues and nitrates
  • Adequate lighting – no more than 12 hours a day, and with sufficient power.
  • A moderate number of fish in the aquarium, with a large number, they create nitrates, which cannot be absorbed by plants.
  • Fish that feed on algae – mollies, ancistrus, loricaria, SAE (Siamese algae eaters), otocinclus, gyrinocheilus.
  • Moderate feeding, rotting food debris is the main supplier of nitrates.
  • Regular cleaning of the aquarium and replacement of some of the water.

Algae in the new aquarium

In newly neglected aquariums, the nitrogen cycle has not yet been established, and they are especially likely to have an outbreak of any types of algae in freshwater aquarium.

The very fact that algae will appear in a new aquarium is normal. In the first 2-10 weeks after starting a new aquarium, you can see the rapid growth of brown algae. This happens if the nitrate level in the water exceeds 50 mg per liter. Filtration and partial water changes solve this problem.

As soon as the plants take root and grow, they will take food from the algae and the growth of the latter will slow down or stop. In an established aquarium, there is always a struggle for balance between plants and algae.

How to get rid of algae in your aquarium?

For example, algae of the genus Aufwuchs (from German for growing on something) grow on hard substrates such as rocks, in both fresh and salt water. Algae, especially green and diatoms, are the primary habitat for small crustaceans, rotifers, and protozoa.

Many aquarium inhabitants feed intensively on algae-overgrown surfaces. Cichlids of Lake Malawi are widely known as fish adapted to the algae diet.

Examples of the type, Labeotropheus trewavasae, and Pseudotropheus zebra, are very characteristic. They have hard teeth that allow the algae to be pulled off the rocks. Mollies look for algae clearings and pluck them. In the marine environment, algae are an important part of the diet of sea urchins, sea worms, and chitons.

I stimulated the algae growth in my cichlid tank to create a natural environment and got the right amount of filamentous algae and diatoms. Thus, depending on the species of fish and biotope from the habitat, growing algae may even be desirable.

Algae are an essential part of the diet of species such as mollies, African cichlids, some Australian fish, and catfish such as the ancistrus or Otocinclus . Frequent water changes will reduce the amount of nitrate in the water and reduce the growth of algae.

In a well-balanced aquarium, abundantly overgrown with plants, the balance of minerals is in balance, the surplus is consumed by plants and any types of algae in freshwater aquarium. And since higher plants always consume more nutrients than algae, their growth is limited.

Why algae appear in an aquarium

The presence of green algae and bacteria in the aquarium not only significantly complicates the process of maintaining cleanliness and spoils the appearance of the aquarium, but also causes great harm to its inhabitants.

Cyanobacteria, for example, secrete toxic substances that, when concentrated, lead to disease and death of aquarium fish and plants. These algae build up dark to blue-green deposits on the soil, plants, equipment, and aquarium decorations and are difficult to remove. At the same time, green algae in the form of threads and dots cover the glass of the aquarium and plant leaves, brown bloom covers the ground, and bundle growths (red algae) affect the leaves of aquarium plants and, actively multiplying, are extremely difficult to eliminate.

To avoid the spread of many types of algae in freshwater aquarium and the resulting unpleasant consequences, strictly adhere to the following recommendations:

  • Feed your fish the right amount of food they can eat in a few minutes. Eaten food contaminates the water and contributes to the appearance of unexpected green inhabitants in the aquarium.
  • The lighting of the aquarium should be optimal. Excess light provokes the rapid growth of algae.
  • Once every 2 or 3 weeks, replace up to 1/3 of the water in the aquarium, preferably with the addition of a water treatment agent (TetraAqua AquaSafe). it effectively neutralizes chlorine and binds heavy metals.
  • Thoroughly clean inventory and decorative items before placing them in the aquarium.
  • If you have a lot of fish, purchase multiple tanks. Overpopulation of the aquarium and high concentration of waste products create favorable conditions for the emergence and rapid growth of algae. With the proper arrangement of the aquarium, the following calculation is observed: 1 liter of water per 1 cm of the fish’s body length.
  • Monitor the condition of the aquarium plants, use good quality soil (TetraPlant), and top dressing.
  • Regularly monitor water parameters (NO3, CO2, etc.) and make sure that the indicators do not go beyond the normal range.
  • Maintain optimal water circulation in the aquarium as too little circulation creates favorable conditions for the growth of algae.

If algae have already appeared in the aquarium, use special products to remove them (TetraAqua AlguMin, TetraAqua Algizit, etc.). Quality products not only effectively destroy algae, but also prevent their reappearance for a long time without the slightest harm to the fish.

Taking care of your aquarium fish starts with taking care of your aquarium. Be careful, follow the recommendations, and let the little water corner in your house please the eye for a long time!


Methods of fighting algae

Methods for fighting and getting rid of many types of algae in freshwater aquarium

So, here are the basic and effective methods of dealing with green, brown, brown, black, blue-green bloom-algae.

It is very important to determine what types of algae in freshwater aquarium you have.

Like plants, there is a big number of algae in freshwater aquariums, as well as their species and subspecies. Of course, it is not possible to know all of them, but you need to know the group, the genus of these algae! The effectiveness of the struggle and the actions that need to be taken depends on this.

This is where all the confusion in the advice on the forums lies: turn off the lights, turn on the lights … Everyone has different types of algae, different aquariums, different lighting, water, and aquatic organisms.
Below, in this article, you will see the main and most common types of algae in freshwater aquarium, and the specifics of dealing with them will be described.

Aquarium bio balance is our all

The root cause of any aquarium trouble is the absence or violation of bio balance in the aquarium, that is, the mutual balance of all aquatic organisms (fish, plants, mollusks, algae, fungi, bacteria, etc.).

You will be surprised, but in the aquarium, there are always spores of various algae, as well as bacteria and fungi! All of them perform their function, for example, to cleanse the aquarium from dead organic matter, remove poisons from the aquarium (ammonium, nitrites, and nitrates), etc. In other words, the aquarium is not sterile – it is a living organism, from various groups, colonies of living organisms visible and invisible to humans.

An algae outbreak is visual evidence of a violation (lack) of bio balance in the aquarium. This is the loss of any link in the balance!

Having found out which link dropped out, you need to put it back in place. What is difficult for a beginner to do!

Here are the main reasons for the loss of the bio balance link:

  • Excessive daylight hours in the aquarium or incorrect aquarium lighting. Accordingly, you need to reduce or adjust the daylight hours. Or altogether, if possible, turn off the lights for a couple of days, as a preventive measure.
  • lack of daylight hours or the use of “wrong” lamps with the “wrong” spectrum. Accordingly, it is necessary to increase the daylight hours or remove lamps with a “bad” spectrum and buy lamps of the required spectrum or buy additional lamps of the missing spectrum. Read more Aquarium lighting and lamp selection and DIY aquarium lighting. This point, for example, is relevant for diatoms that appear in “young aquariums” and do not like intense lighting.
  • the presence in the aquarium of an excess of dead organic matter and dirt (dead plants, fish, food residues, waste products of aquatic organisms, etc.). Simply put, the aquarium does not have time to cope with so much “garbage” and the only way out for our beloved, live aquarium is to call for the help of algae, which will happily devour all this garbage.
  • Accordingly, you need to remove all the “garbage”: siphon the bottom of the aquarium, clean the walls, decor, and equipment, mechanically try to remove algae, as well as make more frequent and more complete water changes with fresh water, in the end, you can pour aquarium charcoal into the filter compartment …
  • the next reason follows from the above and is a disastrous continuation of the accumulation of “dirt” in the aquarium. All dead organic matter is decomposed by beneficial bacteria and fungi, and removed from the aquarium. If there is a lot of this dead organic matter and it accumulates, microorganisms do not have time to process it! Poisons begin to accumulate in the aquarium – decomposition products: ammonia, nitrites, and nitrates, which leads not only to the appearance of all possible types of algae in freshwater aquarium but generally destroys all living things in the aquarium.

In addition to the above measures for thorough cleaning of the aquarium, you need to use aquarium preparations that either absorb poisons or contribute to an increase in the colony of beneficial nitrifying bacteria, for example:

  • Zeolite. Sold in pet stores or other places. Fluval Zeo-Carb is a common mixture of zeolite and coal.
    Note: you need to know that aquarium coal is not effective against poisons and only ion exchange resin – zeolite removes them. More …
  • Preparations biostarters, as well as preparations promoting the growth of colonies of beneficial bacteria. Simply put, these are drugs that contain the very bacteria that decompose poisons. There are a lot of such drugs, for example, popular ones: Tetra SafeStar – a colony of bacteria, Tetra NitratMinus, Tetra NitrateMinus Pearls – these drugs for nourishing beneficial bacteria and others.
  • A large number of plants in the aquarium. No one has yet scientifically proven that plants suppress algae, but the fact remains that in an aquarium with live aquarium plants (1/2, 2/3), there are no algal outbreaks, except that sometimes green dots appear, and then from strong lighting. Therefore, if you have the opportunity to provide the plants with proper care: LIGHT, CO2, UDO – be sure to plant the beds!
  • There are useful fish that fight – eat algae and algal bloom:Siamese algae eaters are tireless workers of the aquarium, sometimes it seems that the only meaning of their life is an insatiable desire to kiss all the plants and all stones, and walk through all the aquarium decorations. They can still be found under the abbreviation SAE, which stands for Siamese Algae Eater. There are also CAE and IAE – Chinese and Indian algae eaters. Effective against algae “black beard“, “filamentous algae” and “deer horns” others.Otocinclus are no less effective fish. Thanks to the structure of their mouth, they gently and well remove algae from plants, decor, and walls. Copes with green, brown (diatoms), etc.Ancistrus or bristlenose pleco are also useful. But, unlike the aforementioned fish, adults of ancistrus are lazy. Yes, and they say that in addition to algae, they also eat plants.To a good helper in the fight against algae, the whole family of Poeciliidae also applies – guppies, xiphophorus, mollies, and others.All possible mollusksapple snail, coils, physa, marisa, etc.Amano Shrimp. Help in the fight against filamentous algae.

Note that you cannot rely on the help of these fish, but not hope.

Finally, aquarium preparations that suppress all types of algae in freshwater aquarium will come to the rescue. Pet stores sell a lot of such preparations, as a rule, in their name they contain the word “Algo” (algae), for example, Tetra AlgoStop Depot.

These drugs should be used carefully, wisely, and according to instructions. We recommend Tetra products, as their preparations contain monolinuron, which has a milder, gentle effect. When used correctly, taking into account all the circumstances in the aquarium, Tetra preparations do not have a negative effect on fish and plants.

Another and a rather extensive group of algae preparations contains glutaraldehyde, an algaecide of more powerful action. It can be used in advanced cases or, for example, in dense herbalist aquariums.

In general, in practice, it has been noticed that if the aquarium is just with fish, then it is better to use Tetra and monolinuron. And if we are talking about a herbalist – an aquarium with plants, then preparations based on glutaraldehyde behave perfectly and are effective. There are a lot of such drugs, including those from domestic brands. Of all the variety, we can recommend a drug for algae from the company Medos VladOx – glutaraldehyde, at an adequate price!