Effective ways to combat algae and life hacks from aquascaping gurus

Every aquarist who is passionate about plants will sooner or later encounter uninvited guests — algae. They appear suddenly: green film on the glass, tufts on the leaves, a slimy film on the surface of the water. This can seriously spoil the appearance of your underwater garden and throw it out of balance.

But don't despair. The appearance of algae is not a death sentence, but a signal. Your aquarium is simply trying to tell you that something has gone wrong with its balance. Most often, the reason lies in an excess of light or nutrients that higher plants cannot consume quickly enough.

Experienced aquascapers have long developed their own strategies for dealing with algae. They use not only force, but also cunning, creating conditions in which algae simply cannot survive. This involves a whole range of measures: from adjusting the lighting and applying fertilizers according to a strict schedule to introducing small helpers into the aquarium — shrimp and snails.

In this article, we will collect the most effective and proven methods. You will learn not only how to deal with a problem that has already arisen, but also how to prevent it from occurring. These life hacks will help you keep your aquarium perfectly clean so that your plants stay healthy and the water remains crystal clear.

Thread algae

Algae got their name from their appearance—they resemble long threads ranging from bright green to almost black in color, which tightly wrap around plants, attach themselves to surfaces, and inhibit plant growth. The most common types are:

How to combat

Mechanical cleaning

The structure of most thread algae is quite fragile, so during the procedure, any remaining algae that cannot be removed are destroyed and cannot reproduce further.

Algae can be removed from leaves using any handy tools, such as tweezers or cotton swabs.

Glass surfaces can be cleaned well with an old plastic card, such as a bank or store card—it works effectively and does not scratch the glass.

Another effective life hack is to use an electric toothbrush. It allows you to remove algae from hard-to-reach places, clean driftwood and other elements without removing them from the aquarium.

Natural enemies

Amano shrimp (Latin name – Caridina multidentata) work best against thread algae. They are often perceived as a panacea for all types of algae, but Sergey Ermolaev, a developer of aquarium care products, claims that this is not entirely true.

They eat thread algae, including cladophora, but the most effective are large specimens – at least 3-4 cm (4 individuals per 10 liters of water).

Another helper in the fight against thread algae is neocaridina shrimp. They are cheaper than Amano shrimp, but only consume soft varieties of algae.

Chemical preparations

Aquayer AlgoShock is considered the most effective in combating thread algae. Instructions for use: add 8 ml of the product to 50 liters of water daily for 3 days; in case of large-scale infestation, the dose can be increased to 12 ml.

In case of large-scale infection, it is necessary to restart the aquarium with mandatory replacement of the substrate.

It is recommended to use substrates that do not contain nitrates and phosphates, and to carefully monitor the water parameters during the first month.

Pay special attention to lighting when starting or restarting the aquarium. If it is possible to slightly reduce the light intensity at first, then you should do so until the microflora in the tank stabilizes.

— Filipe Oliveira, renowned aquascaper

Black beard

A type of algae that feeds on organic debris and resembles a tangle of black or green filaments. Black beard quickly covers plants and aquarium surfaces, and it can be difficult to deal with.

How to combat it

Natural enemies

Siamese algae eaters can be used to eliminate black beard algae. To keep the aquarium clean, it is enough to keep two small fish in the tank.

The disadvantage is that in the absence of algae, they may start to feed on moss or other plants.

Red-nosed shrimp (Caridina gracilirostris) can be used, but they are quite difficult to maintain.

Sidex

• This product is used in medicine to disinfect surfaces, but recently it has been recommended for combating black beard algae.
• Sidex is added once a day at a dosage of 10-15 ml per 100 liters of water. The dosage is gradually increased to 20-25 ml, and the full course lasts about two weeks.

• Aquascapers and aquarists who have used this method in practice claim that it does not harm fish or plants, but it is better not to increase the dose. There have been cases where some aquarium inhabitants died when more than 30 ml of the product was added.

Nathan Hill

Aquascaper and editor of PracticalFishkeeping magazine

Destroy black beard algae with glutaraldehyde (25% solution and 75% water). The decorations should be soaked in the liquid, then rinsed and returned to the aquarium. After that, add 4-8 ml per 50 liters of water for a week.

— Nathan Hill Aquascaper and editor of PracticalFishkeeping magazine

Chemical preparations

Aquayer Algaecide+CO2 can be used to combat black beard algae. The dosage is 4-8 ml per 50 liters of water during an algae bloom, and the treatment course is 3-7 days.

For intensive treatment, turn off the filters for half an hour and treat the infected surfaces with a syringe.

Acetic acid

Immerse the infected plants in a 3% vinegar solution (only the tops, do not touch the roots!), then rinse them in aquarium water and replant them.

Apple cider vinegar can be used instead of acetic acid.

To prevent black beard algae from reappearing, you need to constantly siphon the substrate, removing organic debris, and also pay attention to the choice of fish food — it should contain a minimum amount of phosphorus.

You can fight algae in an aquarium not only with chemicals — the key to cleanliness lies in balance: proper lighting, moderate feeding of fish, and regular water changes. Many aquascape gurus advise planting more fast-growing plants — they take nutrients away from algae. Helpful “cleaners” such as apple snails or shrimp also help. And don't forget: clean glass and healthy vegetation are not the result of ideal conditions, but of constant care and attention to detail.

Vietnamese weed

A common “guest” in aquariums with an unstable nitrogen cycle. It resembles black beard algae, but is tougher (it clings firmly to any surface) and more resilient, so it takes longer to combat.

How to combat it

Chlorine and other agents

A radical way to combat Vietnamese moss is to thoroughly wash all surfaces with chlorine or any product containing it (for example, bleach). The product is diluted in a ratio of 1 to 20, objects are soaked in the solution for several days, and plants are immersed up to the roots for 7 minutes.

After that, all treated elements are rinsed for half an hour. The disadvantage is that if even a minimal amount of Vietnamese weed remains on the surfaces, it will start to grow again. Instead of chlorine, you can use Sidex or 7% vinegar diluted with water in a 1:2 ratio. These agents are gentle but not as effective.

Natural enemies

Diatoms have a rigid structure, so they have few natural enemies—fish and most shrimp cannot cope with them. Most often, aquarists introduce ampullaria snails, but reviews of their effectiveness are quite controversial.

Mariz snails can also help combat Vietnamese waterweed – the optimal number is 10 per 30 liters of water. After cleaning, they must be removed, otherwise they will start eating the plants.

Since it is quite difficult to combat Vietnamese algae, it is better to use several methods in combination. Preparations that act against black beard algae (Aquayer Algaecide+CO2, Tetra AlguMin) cannot completely destroy the algae, but they destroy its structure, after which it becomes easier for snails to absorb it.

Diatoms (brown algae)

Diatoms, or diatom algae, are a continuous brown coating that covers plants and surfaces. They most often appear in new aquariums and are very fond of low light levels.

How to combat them

Mechanical cleaning

• Diatoms can be cleaned from glass and leaves with a soft cloth, and from the soil it can be easily sucked out with a siphon.

• After that, it is necessary to increase the lighting, and the algae usually die.

Natural enemies

To combat diatom algae, you can use Gyrinocheilus aymonieri or Otocinclus affinis. These fish have a special sucker-like mouth structure, so they are good at dealing with algae in the form of plaque.

To combat algae, it is recommended to keep one fish per 40-50 liters of water.

The difference is that otocinclus are more sensitive to water parameters, can be sluggish, and do not perform their task well.

Chemical preparations

Tetra AlguMin and Tetra Aqua Algo Stop depot are the most effective against diatoms. Add 5 ml of Tetra AlguMin per 10 liters of water, and after treatment, remove as much algae as possible mechanically.

Repeat the procedure after 3-4 weeks. Tetra Aqua Algo Stop depot are slow-dissolving tablets (1 per 25 liters of water). They should be placed in the substrate in areas with free flow. They do not lose their shape, but after 6 weeks they should be removed, as they will no longer release active substances.

Diatoms are usually easy to remove, and if you maintain optimal lighting levels and use filtration, the problem will not return.

To suppress algae growth, experienced aquascapers recommend using lamps with a predominantly red spectrum. Algae are poorly adapted to absorbing them, so this method is very effective when used in combination with other means.

Blue-green algae

The difference between blue-green algae and other types is that they are bacteria, not single-celled organisms. They look like a green slimy film that covers plants and soil.

How to combat

Antibiotics

Since blue-green algae are pathogenic microorganisms, they can be controlled with common antibiotics sold at pharmacies.

Erythromycin is considered to be the most effective, with a dosage of 0.25-0.5 g (1-2 tablets) per 100 liters of water.

They can be dissolved in a small amount of liquid and poured into the aquarium after removing the adsorbents from the filter.

After 24 hours, the water should be changed (30-50%) to remove excess antibiotic.

Erythromycin is considered safe for fish and plants, but some particularly sensitive specimens may die after its use. To prevent negative effects on aquarium inhabitants, it is important to follow the dosage exactly.

Shading

The authorship of this method is attributed to the legendary Takashi Amano. To eliminate the problem, you need to clean it of algae as much as possible, turn off the lighting, and cover the aquarium with a dark cloth.

The supply of carbon dioxide should also be stopped, but the water should be aerated heavily. Leave the aquarium for 3 days, then introduce Amano shrimp and otocinclus catfish. The disadvantage is that some light-loving plants may die during the “dark” period.

Shading can be used to combat blue-green algae and when the water is heavily bloomed, which is also caused by light-sensitive pathogenic microorganisms.

Xenococcus

These algae live in almost every aquarium, but only begin to actively multiply when there is an imbalance in the system. They look like green dots that merge into a continuous film, with slow-growing specimens such as anubias, staurogyne, etc. suffering the most from xenococcus.

How to combat it

• algae must be removed from surfaces using scrapers or improvised tools (toothbrushes, etc.);
• gyrinocheilus or Otocinclus fish can be used as natural enemies.
• aquayer Algaecide+CO2 is recognized as an effective remedy—the preparation should be applied to infected surfaces using a syringe, after turning off the filters for half an hour.

• Tropical Algin (1 ml per 10 l of water) and JBL Algol (a 100 ml bottle is designed to treat 400 l of water) are effective;
• it is recommended to plant fast-growing plants (hornwort, Vallisneria, Hygrophila) in an infected aquarium to regulate the excess of nutrients that cause the appearance of xenococcus.

After cleaning the aquarium, the lighting should be adjusted—red and “cold” lamps should prevail, as yellow light increases the likelihood of xenococcus appearing.

So, fighting algae is not a war of destruction, but rather a matter of establishing balance in your underwater world. The most effective methods are always comprehensive: proper lighting, regular water changes, reasonable amounts of food, and live plants as your main allies.

Don't panic at the first signs of a green outbreak. Often the problem can be solved by simply adjusting the equipment or changing habits. Remember the life hacks from experienced aquascapers: a net for cleaning surfaces, fast-growing helper plants, and regular hydrogen peroxide for spot treatment.

The main thing is to be patient. An aquarium is a living system, and it needs time to return to normal after your actions. Observe, experiment in moderation, and learn to understand the language of your water body. Over time, controlling algae will become as natural a part of care as feeding fish.