Algae can be a real nuisance in aquariums as not only does it look unsightly, it can also be an indicator of an underlying problem, including excess nutrients and too much light.
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Fortunately, the issue can be resolved with algae eating fish or invertebrates. These aquatic creatures will happily consume the pesky substance to help you achieve a healthy ecosystem and clean aquarium.
But it’s important to choose the right algae eaters for the type of algae in your fish tank and volume of your aquarium.
When I first started keeping fish over 10 years ago, I had a lot of issues with algae. My local fish store told me a common pleco was the answer to my problem.
However, after doing some research, I discovered that these fish can grow up to 20 inches and need at least a 75-gallon tank. I only had a 10-gallon tank at the time, so it was completely the wrong advice!
That’s why I’ll be going over some of the best algae eaters for different sized aquariums and types of algae so you choose the correct one for your setup.
What Are Algae Eaters?
Algae eaters are fish or invertebrates that consume algae as part of their diet. Some algae eaters feed solely on this substance, while others eat it alongside other food sources.
Do Algae Eaters Keep Your Tank Clean?
Yes, algae eaters can help keep your tank clean by consuming algae and biofilm. This not only promotes a healthy aquatic ecosystem, but also makes your aquarium cleaner and look tidier. Although they help reduce algae, don’t expect them to remove full blown algae blooms.
Types of Algae
There are many different types of algae that can appear in fish tanks, from brown algae (diatoms) to the more recognizable green spot algae.
Some algae eaters have specific feeding preferences to certain algae. For instance, otocinclus mostly eat brown algae.
It’s crucial to know the type of algae you’re dealing with so you can choose the right algae eater for your tank.
Hair Algae
Hair algae, also known as thread algae and soft filamentous algae, is a type of green algae that forms into long, thick coats that are made up of threadlike pieces. It can cover an entire aquarium in its sheets if left to overgrow.
Brown Algae
Despite being called an algae, brown algae isn’t actually an algae – it’s made up of tiny microorganisms known as diatoms. It’s common in new tanks that have recently undergone the cycling process.
Blue Green Algae
Blue green algae is a type of cyanobacteria, so it isn’t technically an algae. Like live plants, it uses photosynthesis to grow. It is usually a blue-green color, but it can occasionally be hues of red, brown, and black.
It can emit a foul odor and quickly overtake your aquarium if it is not removed. In addition, blue green algae can be harmful to plants and fish as it produces toxins.
Black Beard Algae
Black beard algae (also known as brush algae) is a type of red algae that grows in small, fuzzy tufts that resemble a beard. It first appears as black dots, but will eventually grow outwards into furry clumps.
It commonly grows on the tips of plants, particularly slow-growing species like java fern and anubias. Very few fish and invertebrates eat black beard algae, so it can be difficult to eradicate.
Green Spot Algae
Green spot or green dot algae appears as small green dots, usually on the aquarium glass, but it can also grow on decorations and plants, especially slow-growing species like anubias.
What Are the Best Algae Eaters?
There’s no definitive answer regarding the best algae eaters as it largely depends on the size of your tank and the type of algae in your aquarium.
For example, oto catfish mostly feed on diatoms, so they may not be the right option for your setup if it is overrun with brush algae.
On the flip side, a common pleco is a large fish that needs ample space, so they’re unsuitable for nano tanks.
To help you make the right choice for your setup, I’ll be going over some of the best algae eating fish and invertebrates for large and small tanks, as well as specific algae types.
Bristlenose Pleco
Common Name(s): Bristlenose pleco, bristlenose catfish, bushynose pleco, bushynose
- Scientific Name: Ancistrus cirrhosus
- Origin: South America
- Length: 3-5 inches
- Care Level: Easy
The bristlenose pleco is one of the best algae eating fish for a freshwater aquarium as they are entirely herbivorous. They are native to South America, primarily the Amazon River Basin in fast-flowing waters.
The bristlenose catfish gets their name from the whisker-like bristles they have around their mouth, which are more prominent in males.
They are typically brown, green, or gray in color with yellow or white spots, though other variants like albino and red also exist. These fish grow to around 3 to 5 inches in length and produce a lot of waste, so at least a 30-gallon aquarium is necessary.
While their main food source is algae, you’ll need to supplement their diet with vegetables (zucchini, romaine lettuce, cucumber, and kale are some good options) and spirulina wafers to keep them healthy. They also require driftwood to help with digestion.
Siamese Algae Eater
- Common Name(s): Siamese algae eater, Siamese flying fox, flying fox, Siamese fox
- Scientific Name: Crossocheilus siamensis
- Origin: Southeast Asia
- Length: 6 inches
- Care Level: Easy
Another excellent freshwater algae eater is the popular siamese algae eater – the truth is in the name! They originate from Southeast Asia in areas like Thailand and Malaysia.
Siamese algae eaters have long, slender bodies that are brown-beige in color with a black stripe that runs along the center.
Size
These fish reach approximately 6 inches in length, so a tank size of a minimum of 30 gallons is essential.
Like their name suggests, Siamese algae eaters mostly eat algae (they particularly like thread algae), though they also eat plant matter, periphyton, phytoplankton, insects, and small dead fish.
It’s important to note that Siamese algae eaters and Chinese algae eaters are not the same fish species despite their names often being used interchangeably.
Although both great algae eaters, they have completely different appearances and natures. A true Siamese algae eater is relatively peaceful, whereas a Chinese algae eater is aggressive and can harm other fish.
Otocinclus Catfish
- Common Name(s): Otocinclus, otocinclus catfish, oto, dwarf sucker catfish, dwarf armored catfish
- Scientific Name: Otocinclus macrospilus
- Origin: South America
- Length: 1.5-2 inches
- Care Level: Moderate
Otocinclus catfish are one of the best algae eaters as their entire diet revolves around algae and biofilm. They are native to South America.
Growing to just 1.5 to 2 inches in length, these tiny catfish need around a 10-gallon aquarium to comfortably house 4 or 6. They need to be kept in schools of at least 4 (ideally 6), otherwise, they can be extremely timid.
They come in various colors and patterns, but their most common appearance is light gray, green, or brown with a black horizontal line down their body.
Otocinclus can be finicky eaters as they have a strong preference for diatoms, though they will eat soft green algae and some other types. Make sure to supplement their diet with spirulina wafers and blanched veggies like cucumber and zucchini.
Ghost Shrimp
- Common Name(s): Ghost shrimp, glass shrimp, eastern grass shrimp
- Scientific Name: Palaemonetes paludosus
- Origin: South America
- Length: 1.5 inches
- Care Level: Easy
Ghost shrimp make fantastic members of the clean-up crew in your aquarium as they are scavengers that will eat algae, biofilm, dead fish, and decaying plant matter. They are native to South America.
As you may have already guessed from their name, ghost shrimp are almost entirely clear, though they are often covered in tiny spots of dark brown or green.
Ghost shrimp have low bioloads and only grow to around 1.5 inches in length, so you can keep a small group in as little as 5 gallons. Feed them fish flakes/pellets, algae wafers, veggies, and live or frozen foods like bloodworms to keep them healthy. Also watch out for predatory fish because they can become a target.
Rubber Lip Pleco
- Common Name(s): Rubber lip pleco, rubber lipped pleco, rubbernose pleco, bulldog pleco
- Scientific Name: Chaetostoma milesi
- Origin: South America
- Length: 5-7 inches
- Care Level: Easy
If you’re looking for one of the best algae eaters for a freshwater tank, the rubber lip pleco is a solid choice. These fish originate from South America and reach 5 to 7 inches in length.
Rubber lip plecos are bulky, fierce-looking fish (though they are the exact opposite!) that are usually gray, brown, or an olive green color.
They need at least a 30-gallon fish tank as they make a lot of mess. They are herbivores, so they will happily consume any algae in your aquarium, but you can also offer them blanched vegetables and algae wafers. Be sure to have driftwood in your tank, too!
Ramshorn Snail
- Common Name(s): Ramshorn snail
- Scientific Name: Planorbarius corneus
- Origin: North America
- Length: 1-2 inches
- Care Level: Easy
Ramshorn snails are one of the best algae eating snails, in addition to being great clean-up crew members as they graze on uneaten fish food, decaying aquatic plants, and other debris.
They are native to North America and can be found in areas such as Alaska, Florida, and northern arctic Canada. They are an air-breathing freshwater snail, so they use a lung-like organ to store air underneath their shells.
Ramshorn snails come in a huge variety of colors and patterns, including brown, blue, and red. Their shells have a unique spiral shape, which is where they get their name.
Size
As these freshwater snails only grow to 1 to 2 inches in size, they can be kept in a nano freshwater aquarium like a 5-gallon. They are scavengers, so they’ll munch on algae, leftover fish food, dead fish, and decaying plant matter.
However, ramshorn snails can eat live plants, particularly species with delicate leaves, so this is something to keep in mind if you have a planted tank.
Common Pleco
- Common Name(s): Common pleco, spotted pleco, suckermouth catfish, janitor fish
- Scientific Name: Hypostomus plecostomus
- Origin: South America and West Africa
- Length: 20 inches
- Care Level: Easy
The common pleco is a great algae eating fish for freshwater aquariums, like many other species of omnivorous and herbivorous plecos. They’re native to South America and West Africa.
These gentle giants can grow impressively large, often up to 20 inches in length, so they need at least a 75-gallon freshwater tank. Common plecos are peaceful fish, so they can be housed with other species that are equally as passive.
They have long fins, a large mouth, and a flat stomach. Their base color is brown with lighter colored splodges.
As common plecos are omnivores, they’ll eat both plant matter and meaty foods, so feed them algae wafers, blanched veggies, and high-quality flakes or sinking fish pellets.
Cherry Shrimp
- Common Name(s): Cherry shrimp
- Scientific Name: Neocaridina davidi
- Origin: Taiwan
- Length: 1-1.5 inches
- Care Level: Easy
Cherry shrimp are a great little addition to a freshwater aquarium overrun with algae as they will happily graze on it, as well as help keep your tank clean.
These little shrimp are native to Taiwan and are normally a dull brown or green color, but they have been selectively bred to have a multitude of other colors like red, green, blue, orange, yellow, and black.
Size
As they only reach around 1 to 1.5 inches in length, you can have a small colony in as little as 5 gallons.
Avoid placing them with big predatory fish. Cherry shrimp make good tank mates for small fish that won’t view them as prey like chili rasboras, emerald-dwarf rasboras, and ember tetras. Additionally, small crabs such as Thai micros can be introduced as compatible tank mates for cherry shrimp, further adding to the diversity and dynamics of the aquarium community.
While they’ll eat algae, decaying plant matter, and uneaten fish food, you can also offer them spirulina wafers, sinking shrimp pellets, and vegetables like zucchini.
Chinese Algae Eater
- Common Name(s): Chinese algae eater, sucking loach, honey sucker
- Scientific Name: Gyrinocheilus aymonieri
- Origin: Southeast Asia and southern parts of China
- Length: 5-7 inches
- Care Level: Moderate
The Chinese algae eater is a good algae eating fish, though their appetite for the substance is at its strongest while they are young. Although they’ll consume algae once mature, they’ll need other sources of food to keep them healthy.
Chinese algae eaters originate from Southeast Asia and the southern side of China. They have elongated, slender bodies that are light brown with dark stripes. However, other variants like albino and honey are also available.
Size
In the wild, these algae eating fish often grows to 11 inches in length, though they usually max out at around 7 inches in captivity. An adult fish requires at least a 55-gallon aquarium, though juveniles can be housed in smaller tanks.
Chinese algae eaters are aggressive fish, so they are not ideal for community setups. It’s best to house them in species-only tanks, but if you want to give them roommates, select fast-moving fish species like danios and molly fish.
Young Chinese algae eaters can suffice on aquarium algae, but as they mature, you can feed them veggies, algae wafers, and live or frozen foods like blackworms, daphnia, brine shrimp, and bloodworms.
Amano Shrimp
- Common Name(s): Amano shrimp, Yamato shrimp, Japanese shrimp, and algae shrimp
- Scientific Name: Caridina multidentata
- Origin: Taiwan and Japan
- Length: 2 inches
- Care Level: Easy
Another one of the best algae eating shrimp is the Amano shrimp, which originates from Taiwan and Japan. They’ll eat pretty much any type of algae, including brush algae, most types of string algae, and even black beard algae.
This shrimp species reaches around 2 inches in size and has a translucent body with hues of green, reddish-brown, or light brown. They also have small dots or dashes over their body.
A pair of amano shrimp need at least a 5-gallon tank – it’s a good idea to allow for 2 gallons of space per shrimp. These algae eating shrimp are entirely peaceful and make great tank mates for other shrimp, passive freshwater fish, and aquatic snails like mystery snails.
Amano shrimp are scavengers, so they’ll consume plant algae, leftover food, dead fish/shrimp, and decaying plant matter, but you can supplement their diet with sinking shrimp pellets, veggies, and spirulina wafers.
Mystery Snail
- Common Name(s): Mystery snail, mystery apple snail, spike-topped apple snail,
- Scientific Name: Pomacea bridgesii
- Origin: South America
- Length: 1.5-2 inches
- Care Level: Easy
Mystery snails are another excellent species of algae eating snails for freshwater tanks. They are native to South America, but they have also been found in Florida, Hawaii, and Southeast Asia as an invasive species.
Size
The mystery apple snail grows to approximately 1.5 inches in size, though some specimens can reach up to 2 inches. They have smooth, round shells with a whorl, like most other snails.
Mystery snails come in a vast number of shell colors, including purple, brown, green, blue, and yellow, making them one of the most vibrant freshwater algae eaters.
Tank Requirement
A single snail requires at least a 5-gallon tank as they have fairly high bioloads. They can be housed with nano fish, shrimp, and other snails.
Mystery snails are herbivores, so they’ll eat algae, alongside detritus, dead plant matter, and biofilm.
However, they can occasionally nibble on live plants, particularly if they are not getting enough food from other sources.
Flagfish
- Common Name(s): Flagfish, American flagfish, Florida flagfish, pupfish
- Scientific Name: Jordanella floridae
- Origin: Florida
- Length: 2.5 inches
- Care Level: Easy
The flagfish is a fantastic fish to tackle algae growth – they are also one of the only algae eaters to eat hair algae! They are native to Florida where they inhabit shallow, heavily planted freshwater canals, marshes, and ditches, though they are sometimes found in brackish waters.
Flagfish only reach around 2.5 inches in length, so a pair is ideal for nano tanks like a 20-gallon. They prefer to be housed with their own kind and will even school together if kept in small groups.
The flagfish is a very beautiful fish – their coloration resembles the American flag and features a striking iridescent sheen.
As they are omnivores, make sure you offer them high-quality flake food, blanched veggies, and live or frozen foods like daphnia and brine shrimp.
Nerite Snail
- Common Name(s): Nerite snail, horned nerite
- Scientific Name: Nerita
- Origin: Africa
- Length: 1 inch
- Care Level: Easy
If you need a great freshwater algae eater, nerite snails are a solid choice. They’ll eat most types of algae, including green spot algae, diatoms, and soft film algae.
Native to Africa, nerite snails inhabit freshwater and brackish waters. They are available in many varieties, though their most common shell appearance is gold/yellow with black pinstripes.
Make sure you house a single snail in at least a 5-gallon tank due to their heavy bioloads. They are non-aggressive, so you can keep with other passive species of fish and invertebrates.
Nerite snails are herbivorous, making them one of the most effective algae eaters. Alongside algae, nerite snails will eat detritus, biofilm, and dead plant matter, but you can also offer them vegetables and spirulina wafers.
Twig Catfish
- Common Name(s): Twig catfish, whiptail catfish, Farlowella catfish
- Scientific Name: Farlowella acus
- Origin: South America
- Length: 5-7 inches
- Care Level: Moderate
One of the top algae eating fish is the farlowella twig catfish, which like their name suggests, resemble a tree branch! They are long and thin with a pointed nose. Their brown-green coloration allows them to blend into the environment with ease.
They reach between 5 to 7 inches, so be sure to keep them in at least a 35-gallon aquarium, ideally with bogwood and lots of plants. Although not schooling fish, they do best when kept in pairs or small groups.
Twig catfish are extremely peaceful, so they will not thrive if housed with aggressive fish. Choose passive fish species like the cory fish, rasboras, and tetras, or other algae eating fish.
Twig catfish are omnivorous, so they need a good balance of plant matter and meat-based foods. They will scavenge the bottom of the tank for leftovers, algae, dead plants, etc, but you’ll need to offer them sinking fish food pellets, spirulina wafers, veggies, and frozen or live foods like brine shrimp.
Molly
- Common Name(s): Molly, molly fish, common molly
- Scientific Name: Poecilia sphenops
- Origin: North and South America
- Length: 4-4.5 inches
- Care Level: Easy
The last algae eater fish I recommend is the Molly, which are native to North America and South America.
Mollies normally reach between 4 and 4.5 inches in length, so they can be comfortably kept in a 20-gallon tank.
These freshwater fish enjoy the company of their own kind, so be sure to house them in groups of at least 4. Mollies are available in a huge selection of colors and patterns, such as red, marbled, orange, white, and yellow.
While they’ll happily munch on algae, they are omnivores, so supplement their diet with high-quality fish flakes, live and frozen foods, and the occasional veggie.
FAQs
What Causes Algae in An Aquarium?
Excess light and an imbalance of nutrients are the main causes of algae in an aquarium. For instance, keeping your fish tank near a window or using aquarium lights regularly for more than 12 hours a day can lead to algae blooms.
What Are the Best Brown Algae Eaters?
Otocinclus catfish are possibly the best freshwater algae eaters for tackling brown algae growth as it is their main food source. Other algae eaters of diatoms are nerite snails and amano shrimp.
What Are the Best Hair Algae Eaters?
Flagfish, mollies, Siamese algae eaters, and ghost shrimp are among the best hair algae eaters.
What Is the Best Algae Eater for Your Tank?
This mostly depends on the volume of your aquarium and the type of algae you want to eradicate, but I personally think bristlenose plecos and otocinclus catfish are both fantastic choices for relatively small tanks.
Common plecos and Siamese algae eaters are great options for larger aquariums.
Bear in mind that bristlenose plecos need a minimum of 30 gallons for a single fish and otocinclus need at least 10 gallons for a school of 4 to 6.
The common pleco and Siamese algae eater need a minimum of 75 gallons and 30 gallons respectively.
There are other methods to remove algae in your tank, too, including using algae removal products and algae scrapers.
Final Thoughts
I hope this guide helped you choose the best algae eaters for your tank and gave you some valuable information on the most common algae types in aquariums.
Which algae eating species is your favorite? I’d love to hear what you think on our social media platforms and some photos of your new algae eating pet! Be sure to share this post with other fish fanatics so they can learn a new thing or two about algae eaters.
If you’re looking for more helpful tips and tricks on all things fish, take a look at our many other great articles.
