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How to Get Rid of Algae in Fish Tank in Easy Steps?

Algae in a pool can negatively affect the quality of the water, which is why they must solve as quickly as possible. They will make it hard to maintain the preferred water conditions for your fish to prosper.

Low water conditions can make fish susceptible to diseases. The algae growth can also damage aquarium filters and equipment.

Apart from affecting the quality of water, algae look terrible in an aquarium, as it changes the appearance of the aquarium wall, décor, and plants.

A large infestation of algae will also create a welcoming environment for microorganisms, including E Coli, which is harmful to both fish and humans.

This detailed guide contains tips on how to get rid of algae in an aquarium using chemicals or naturally.

How to get rid of various types of algae?

Green Algae

Green algae

Blue-green algae can turn the aquarium murky and green. It causes due to an excess of phosphate and nitrate in the water.

Blue-green algae are cyanobacteria that appear as a slimy blanket covering the plants, substrate, and aquarium décor. The algae grow in both water and wetland. The type that grows on land is known as Nostoc algae.

Algae eaters won’t eat green algae. You should improve the aquarium upkeep and increase the water circulation using a powerhead or air stone to prevent this type of bacteria in the tank.

Moreover, keeping the aquarium in the dark for a week can also remove blue-green algae from the tank. If you have plants in the aquarium, the best way to eliminate green algae is by vacuuming the substrate, replacing water, and treating the tank using antibiotics.

You can use a packet of Maracyn made of the antibiotic erythromycin for 10 gallons of water. Let it sit in the water for a week, and then change the water. You may also have to repeat the process multiple times for the stubborn growth of blue-green algae.

Green Spot Algae

Green spot algae appear as small, green spots on the walls of the aquarium. The slow-growing algae are difficult to remove. An imbalance of phosphate and too much light promote the growth of green spot algae.

To remove green spot algae from the tank, you should use an acrylic or glass-safe algae scraper with a blade attachment. Can use the extension to remove algae from the walls of the aquarium.

Brown Algae

Brown algae

Brown algae are diatoms that occur in both saltwater and freshwater aquariums. They generally remain hidden from sight. But inadequate water conditions can make them visible in the tank – a condition known as the diatom bloom among aquarists.

Mossy brown algae require phosphate and nitrate to thrive. They also need silica to survive in the tank. The abundance of silicates in the fish tank will result in the diatom bloom.

The silicate level in the aquarium will increase when you add a new substrate to the tank. Adding marine salt mix and live rock can also lead to an elevated brown algae level inside the aquarium.

Brown algae will feed on the silicates and die out over time. But this may take months. The light requirement for the brown algae grows low, due to which it can also grow in a new aquarium installed in a dark place.

The growth starts at the aquarium’s corners and quickly covers the walls, decorations, substrates, and plants.

Reef tanks are particularly susceptible to brown algae growth due to the salt mixes that contain silicates. The aquarium’s silicate level should be 0.5 PPM in the aquarium for the development of brown algae.

You can get rid of brown algae in the aquarium using an algae scraper. Use the scraper to remove the algae from the walls and substrates. Unlike green algae, you don’t have to scrub to remove the brown algae. The diatoms will peel off easily through wiping.

To remove brown algae from decorations, you should soak them in a mixture of water and bleach. The water used in the bleach mixture should be dechlorinated water. So, you may need to use a de-chlorinator first before mixing it with bleach to get rid of brown algae.

Mustard Algae

Yellow Algae
Image by u/jat77

Mustard algae, or yellow algae, are sometimes mistaken for dirt or sand in the aquarium. The algae are common in freshwaters. Warm water temperatures encourage the growth of mustard algae.

A lot of newbie aquarists don’t know how to get rid of yellow algae. The algae are stubborn so it is not easy to eliminate them from the tank.

Yellow or mustard algae tend to stick to the walls of the aquarium. Removing the algae from the aquarium will require a lot of scrubbing. You should use the pool brush to remove the algae from the aquarium.

Make sure that you scrub the entire aquarium using a brush. Scrub the area around the filter if you notice any algae growth. We can clean the sand filter using the instructions provided by the manufacturers. The algae can also grow behind the lights and decorative pieces inside the tank.

However, scrubbing alone is not adequate to altogether remove the mustard algae from the tank. You also have to use a diluted solution of bleach to kill the algae.

Consider mixing in the ratio of one part of bleach to about 20 parts of water. Let the décor soak in the bleach mixture for about 15 minutes to get rid of the algae. Empty the bleached water from the bucket and clean using tap water.

Now, fill another bucket with tap water and add a de-chlorinator as per the recommended dosage. Then proceed to soak the aquarium décor in the water for about 15 minutes.

You can also use a chlorine accelerator or a product that is made specifically for removing mustard algae from the aquarium. The solutions mostly use sodium bromide, which is effective against yellow or mustard algae.

Follow the recommendations provided by the manufacturer in shocking the tank to get rid of the algae. You may have to use the solution again after a few days to remove mustard algae from the tank altogether.

Hair Algae

Hair Algae

Hair algae look like wet hair when you take it out of the tank. The algae are also known as staghorn algae, thread algae, and string algae. They can be a nuisance in the tank simply because they multiply. The algae are also not easy to get rid of from the tank.

The algal growth happens by an excess of some nutrients such as iron in the tank. Too much light also contributes to the development of hair algae inside the tank.

You can prevent hair algae’s growth by decreasing food containing iron, increasing fertilization, and reducing the tank’s lighting. You can use a clean-up crew such as Siamese algae eaters, molly fish, and Amano shrimp well to clean up the tank infested with hair algae. To get rid of hair algae in a reef tank, you can manually remove them using a toothbrush.

Black Beard Algae

Black beard algae

Black beard algae are among the most problematic algae to get rid of since most algae eaters do not consume them. The algae grow in bushy clumps that are grey or black. Sometimes the thick chunks are brownish or reddish.

Black beard algae typically grow on driftwood, plants, and aquarium decoration. If you don’t take steps to get rid of the algae, it will take over the aquarium in about a year.

You can use chemicals to get rid of the algae. Spraying liquid carbon directly on the algae will kill the algae.

You can also add it to the water in case of mild cases of algae growth. However, it would help if you were careful since individual plants are sensitive to the liquid carbon solution, such as the Vallisneria.

You can also spray the tank with black beard algae infestation using a liquid solution containing 3 percent hydrogen peroxide.

Just pour the answer on the algal-infested décors or plants for about five minutes, and then rinse them after five minutes. The algae will turn red and die when you spray the solution.

How to get rid of algae in fish tank naturally?

Algae eaters will naturally get rid of algae in the fish tank without using chemicals or bleach.

The algae eaters are generally peaceful that will mind their business eating algae and food scraps in the aquarium.

Here are some of the species that will help you keep control of algae inside the aquarium.

Nerite Snails

Zebra nerite snail

Nerite snails are freshwater snails that only eat algae. They have a peaceful temperament and will not harm the fish, plants, and décors inside the aquarium.

You can keep 5 to 10 Nerite snails in a 20-gallon tank. It would help if you kept these snails in tanks with calm fish.

Mexican Turbo Snails

Turbo snail

Mexican turbo snails are also effective algae eaters. These snails will keep the algal growth in check inside the aquarium. They are particularly effective against brown algae growing in gravel, tank walls, and rocks.

However, these snails are relatively more extensive than other snails and require a large aquarium. These snails are suitable for keeping in a small setup.

Trochus Snails

Banded trochus snail

Trochus snails are also highly effective in keeping the brown algae population in check. These snails can get rid of algae from the surface of the aquarium. Moreover, they have the unique ability to flip themselves, unlike most other species.

Ramshorn Snails

Ramshorn snail

Ramshorn snails are great for planted aquariums since they won’t eat decorative plants. They will eat the algae if there is enough algae growth inside the aquarium.

The snails are compatible with most other peaceful fish.

You can keep the snails in a small aquarium of 5 gallons. The snails grow to a size of about 2 centimeters.

Mystery Snails

Golden mystery snail

Mystery snails are also prolific algae eaters. Snails have eyes and no sensory organs, as is the case with most other snails. They are also easy to feed. These snails can reach a size of 2 inches.

Amano Shrimps

Female amano shrimp

Amano shrimps are famous freshwater algae eaters. They can eat almost all types of algae inside a tank. The shrimp is easy to care for and requires minimal care. Again, you should make sure that they are compatible with your existing fish before introducing them to your aquarium.

Siamese Algae Eaters

Siamese algae eater

Siamese algae eaters are beautiful fish that you can keep in your aquarium for algal control. The fish are one of the best algae-eating fish species. They are attractive and hardy fish species. You will find the fish relentless in cleaning algae from the tank. What’s more, the fish will also eat leftover food inside the tank.

Otocinclus Catfish

Otocinclus eating algae from aquarium glass

Otocinclus catfish are another beneficial fish species that can eat algae inside the tank. Also known as the otos and dwarf suckers, the main benefit of adding the fish species inside the aquarium is their small size. They can squeeze into tight spaces to remove algae from the tank.

Otos grow up to a size of 2 inches, but most of them are smaller. Despite their small size, the fish can eat a large number of algae inside the tank.

They can eat all types of algae but prefer soft green and brown algae. You should put a dozen of these dwarf suckers inside your large tank to keep the algal problem in check.

Bristlenose Plecos

Suckermouth catfish eating grass

Bristlenose plecos are suitable algae-eating fish species. The fish can grow up to about 6 inches. They can consume a lot of algae inside the tank. However, due to their large size, you may want to feed algae pellets to ensure that they had enough.

The fish can eat all types of algae but prefer green spot algae. Most other fish will not eat this type of algae, a favorite of the Bristlenose plecos fish. They also have a huge appetite. It makes them a prolific algae eater that is a must-have in an aquarium to control the algal population.


Black molly

Mollies are generally peaceful fish. They are also good at eating pretty much everything inside the aquarium, including algae. This fish is not considered an excellent algae eater but will do a decent job keeping the algae population checked. They prefer eating algae from live plants and rocks inside the aquarium.

If you are looking for a beautiful-looking fish that will also get rid of algae inside the tank, you should consider adding mollies to the aquarium. They will be a perfect choice, along with shrimp and snails, in getting rid of algae from the fish tank.

Twig Catfish

Twig catfish

Twig catfish are also helpful in preventing algal growth. The fish are also known as the whiptail catfish. They can grow up to about 8 inches in length. The slender-bodied fish can is busy picking algae inside the tank.

Preventive Tips to Keep Algal Growth in Check

It would help if you took preventive measures to prevent out-of-control algal growth. Here are some tips to avoid the growth of algae in your aquarium.

Clean the Aquarium

It would help if you cleaned the aquarium at least once a month. Transfer fish to a separate aquarium, and clean the substrates, plants, and decorative items in the tank. You can clean the aquarium using an aquarium vacuum cleaner or a brush.

Consider buying a robotic aquarium cleaner like AquaGenesis, as it can pick up small debris and fine silt that will improve the aquarium conditions.

Maintain Water Conditions

You should also maintain proper water conditions. Algae thrive in waters with high nitrates, potassium, and iron. Change the water regularly to keep the levels of these nutrients low in the water.

Algae also thrive in water with low pH values. It would help if you used a pH meter to check the alkalinity of the water.

Use a Good Quality Filter

A good quality filter can also help in keeping the water clean. You should run the filter and pump all day long.

Ultra Violet Sterilizers

UV sterilizers are available in most pet stores.

The sterilizer will prevent microbial and algal growth in the tank. It can kill algal blooms before they take over the aquarium.

These devices are not harmful to fish or plants.


The tips mentioned above regarding how to get rid of algae in the fish tank will help you control various types of algae in freshwater and saltwater aquariums.

Remember, being vigilant is essential to prevent algal growth in the tank.

You should clean the tanks regularly and keep algae eaters in the aquarium to maximize the tank’s longevity.

Regular maintenance of the filter will also keep algae growth in check inside the aquarium.