For many hobbyists, algal development in the aquarium is a typical issue. Algae is a natural phenomenon in and of itself. Algae can grow anywhere there is light and water, and it has existed on Earth for a billion years. As a result, you could claim that having some algae in your tank is natural. It can even be advantageous, as ammonia can be used as a food source, and ammonia is a food source for fish and invertebrates, as well as producing oxygen through photosynthesis.

A plague of algae in an aquarium, on the other hand, is typically an indication of an imbalance or excessive pollution levels. Too many algae are ugly, but it can harm fish by raising the pH too high, depriving the tank of oxygen at night, clogging filters, and trapping fish. Black Beard algae, or Brush algae, are a particular nuisance, as they’re incredibly difficult to shift once they’ve taken hold.

Algaecides are available, however, they are strong chemicals that risk causing more imbalance in the water as the algae die off in large numbers, as well as not healing the source of the algae problem. But don’t give up! This complete guide will teach you how to get rid of Black Beard algae and prevent it from reappearing.


Giving nuisance algae less light is one of the simplest ways to combat it. If your aquarium contains living plants, reduce the light to eight hours every day. For optimal results, keep your tank out of direct sunlight. If there are no live plants present, turn the light off while you are not actively viewing the fish and only leave it on for one or two hours per day. Extreme algae outbreaks can also be treated with a “blackout,” which involves covering the entire aquarium with sheets or bin liners and turning off the lights for a few days.

Algae suffer greatly in total darkness, but robust, healthy plants can withstand it. It provides a reset for the tank owner, who can then use various methods to combat the algae once it is lit up again. Reduced lighting, on the other hand, is free and should be the first thing you attempt. Ensure that no sunlight enters the tank at any moment of the day or year, as this may cause algae to grow. Also, an aquarium should not be kept in a conservatory.

In a nutshell, 

  • if your aquarium doesn’t have plants, reduce the amount of light it receives to 6 to 10 hours every day.
  • To control light exposure, connect your lights to automatic timers.
  • If lowering the light exposure isn’t working, try lowering the light intensity.
  • Replace your light bulbs once a year at the very least.


Hydrogen peroxide is available over-the-counter at most drug shops, and it’s a great addition to any hobbyist’s tank treatment arsenal. It’s important to note that you should only use the H2O2 product with a concentration of 3%.

To kill Black Beard algae with hydrogen peroxide, soak any afflicted plants, decorations, or aquarium equipment in undiluted 3 percent H2O2 for three minutes. After soaking, thoroughly rinse everything with freshwater.


If you can’t remove particular things from your aquarium to treat them and you can’t stand the sight of any Black Beard algae, you’ll have to treat the entire tank.

For every 15 gallons of tank water, use 10 mL of undiluted 3 percent hydrogen peroxide. To treat a 30-gallon tank, for example, 20mls of undiluted 3 percent hydrogen peroxide would be required. Directly into the tank, close to the pump output, to ensure that the chemical is equally spread throughout your aquarium. For three days, repeat the procedure once a day.

Within a few days, the algae should begin to decrease in color, and it should die out altogether within a month or two. If the algae persist, repeat the technique with a slightly greater dosage rate.

Your plants may fade little throughout the therapy, but they will be OK. Other animals in your home, such as fish and invertebrates, should be unaffected. You may, however, want to keep your pets in a quarantine tank for the duration of the algae treatment for your peace of mind.


All nutrients in nature are closely cycled, which means that any plant fertilizers are swiftly absorbed and stored by plants. When there are too many fertilizers and too few plants (or no plants) in an aquarium, the free nutrients are readily taken up by algae. Replace the water frequently to keep nutrients low, and if you have plants, apply a liquid fertilizer to boost them and assist them naturally combat algae. If the tank is devoid of live plants, nitrate and phosphate resins can be used to absorb any remaining nutrients and starve the algae.

NB: You also must ensure you don’t overfeed your fish. Overfeeding the fish will result in food waste which algae can then feed on.



The easiest technique to deal with algae is to get your hands in the tank and remove as much as you can manually. Maintaining your aquarium entails several steps.

Frequent water changes: While this is a wonderful idea, changing the water too frequently has various drawbacks, including changing the number of important elements in the water and lowering the population of helpful bacteria. If you have a marine tank, you will also spend extra money on a salt mix. Water changes regularly can become a bother, especially with large tanks.

To remove waste from your fish tank, clean it once a week: Nitrates and ammonia found in fish excrement encourage algal growth. Start by washing the inner glass clean with an algae pad in circular strokes. After that, use a siphon-style vacuum to clean the gravel’s surface. An old toothbrush attached to the end of a siphon tube can be used to suck the algae out as soon as it is dislodged. Finally, wipe off the outside of the tank with an aquarium-safe glass cleaner or a 1:1 solution of vinegar and water dipped in a microfiber cloth.

  • Using your algae pad, remove any decorations.
  • Scrape algae off with a razor blade or a plastic blade if it is difficult to remove.
  • Never allow bleach, soap, or other cleaning agents to enter your water since they can destroy aquatic life and beneficial microorganisms.

NB: Considering the disadvantages of frequent water changes, and how expensive and tiresome it becomes, this third component presents a better option. 

Swap out at least 10% of your water every day until the algae are gone: Every day, remove 10% of the water using a bucket. If you want to avoid hard lifting, either manually remove the water or use a siphon. Fill the tank with filtered water after removing 10% of the water.

  • If you’re adding cold water, make sure the temperature is acceptable for the species of fish in your tank.
  • Use a water conditioner when swapping water.
  • A 10 percent daily swap means you should be switching your water completely every 10 weeks.
  • Do not swap more than 20 percent of the aquarium water daily.
  • For saltwater tanks, add ½ cup (118 grams) of sea salt per 1 gallon (3.8 L) of water and mix it thoroughly.


Many tropical freshwater fish and invertebrates eat algae in addition to utilizing all of the measures outlined above. Add Otocinclus catfish and Algae-eating shrimp to tiny tanks. Mollies, Siamese algae eaters, and Bristlenose catfish are good choices for larger tanks. Black algae will be grazed by all of them, which will assist to keep it at away. However, be cautious when selecting tank scavengers to install, since some of these tank cleansers might cause more problems than they solve.

I. Freshwater Scavengers and Algae-eating Fish

1. Cory Catfish; Bottom-dwelling scavengers, Can be kept with other known peaceful fish species.

2. Loaches (Not all species are suitable as scavengers); Recommended species include Kuhli Loaches, Dojo Loaches, Dwarf Loaches. Don’t involve sucker Loaches in your aquarium as they are known to feed on other fish when fully grown.

4. Pictus Catfish (also called Antenna Catfish); Thrives best in groups of three or four in a planted and landscaped tank

5. Redfin Prochilodus; Aside from being scavengers, they add color to your tank

6. Plecostomus Catfish (commonly known as Plecos); Dedicated algae eaters and the most popular of the catfish species

NB: Snails, P. siamensis (Siamese Algae Feeders), Mollies, Ameca Splendens, Otocinclus, American Flagfish, and various African Cichlid species are among the other freshwater algae eaters.

II. Freshwater Shrimps

1. Bamboo Shrimp; Their limbs have bristle-like structures that can trap and filter food

2. Blue Crayfish; Best kept as a lone scavenger in a tank with a large, fast fish species

3. Prawns (long-armed); Best kept with large fish species however avoid grouping with long-finned species of fish

III. Crabs

1. Hermit crabs; Make sure to provide larger shells where your hermit crab can move into as they grow in size

2. Arrow Crabs; Keep lone scavenger in a tank. Don’t mix with other crabs, shrimp, or small/medium-sized fish

3. Fiddler Crabs; Can be kept singly or with other Fiddler crabs

4. Sally Lightfoot Crabs; Do best when housed with larger fish, quite shy, and needs time to adjust to a new environment.

IV. Saltwater Fish

1. Blenny (particularly the bicolor blenny); Bottom scavengers

2. Butterflyfish; Not too reliable as a tank cleaner for they require a mixed diet

3. Sturgeon and Tang; May have to be fed with vegetable-based food to supplement their diet when algae are not available

4. Wrasse and hogfish; Pick parasites from fish particularly when they are still juveniles

5. Goby; They are Bottom-dwelling scavengers, Carnivores, Live well with shrimps, Compete with fish for food, and are Ideal only for a mature reef. system

V. Saltwater Snails

1. Turbo Snails; They are surface feeders, good glass cleaners but not ideal for rough surfaces

VI. Saltwater Shrimp

1. Coral Banded; These are Notorious scavengers, Aggressive toward very small fish and other species of shrimp, it is Ideal to keep only one

2. Cleaner Shrimp; Best kept in community tanks, and They pick off parasites from fishes

3. Red or Fire Shrimp; They are Used occasionally for parasite control because they eat the protozoan parasite that causes the itch. They are Best singly with large fish species.

VII. Other Saltwater Scavengers

1. Sea Urchins (recommended: Pink Pin Cushion Urchin); Stay away from some species of sea urchins with venomous spines. Favorite meal of the Triggerfish.

2. Starfish and Brittle Stars; They are Bottom scavengers. Although, Some species have been known to attack or eat other inhabitants.


According to one school of thinking, if you plant a lot of healthy, fast-growing aquatic plants, they will naturally combat algae and keep it at bay. Utilize an eight-hour photoperiod this time, fertilize regularly, and use algae eaters. CO2 can also be used to aid in the growth of plants. Plants, on the other hand, can fight algae by growing across the surface and shading the algae beneath them, by absorbing nutrients more quickly, and, according to some, by producing natural algaecides to prevent algal from forming on their leaves. Algae should not be a problem if you create a natural ecosystem. Start with one or two plants and gradually increase the number as needed.

  • For the greatest results, use Java Moss, Amazon Sword, Java Fern, Hornwort, Dwarf Lilies, Water Wisteria, and Crypt Wendtii.
  • After you’ve added plants, keep a watch on the algae levels to see how they’re affecting things. Increase the number of plants if the algae levels do not change.
  • Keep in mind that some plants aren’t suited to high-powered filters. Find a happy medium between filtration, your fish species, and the plants you can keep them with.