After more than 30 years of keeping tropical and cold-water fish, I think it fair to say I have had my fair share of battles with algae. Green Spot Algae, Brown Diatom Algae, Hair Algae, Black Beard Algae, at one time or another I have fought against all of them.
Whilst I don’t actually consider algae to be a bad thing for an aquarium as such, I just don’t want it to cover every surface in my tanks. There are numerous ways to keep algae under control, and keeping fish and other aquarium inhabitants that actually choose to eat it is probably the easiest way.
I currently have a fish room with close to 100 tanks, and many of those tanks are set up as community tanks with more than one species. In almost every one of those tanks, I have at least one species that chooses to eat algae.
In this article, I look at 21 species of fish, shrimp, and snails that will be on your side in the battle against algae.
1. Otocinclus Catfish
The Otocinclus is one of the stalwarts of the algae-eating world. Apart from possibly being the most peaceful fish in the hobby, Otocinclus are algae-eating specialists.
Otocinclus catfish, which are also sometimes referred to as Ottos or Dwarf Suckermouths, only grow to around 2″ (5cm) in length. Their small, slender bodies allow them to fit into the tiniest gaps and crevices, either between rocks or under pieces of wood.
Otocinclus catfish have mouths that are perfectly designed for scrapping soft, diatom algae off of flat surfaces like rocks or the aquarium glass. Otocinclus are so good at eating diatom algae, especially brown diatom algae, that they are often the first fish to be added to a new tank.
Brown diatom algae usually shows up during the first weeks of a new tank, so having a few Ottos in there helps keep the diatom algae under control.
Many people don’t realize that Otocinclus are actually schooling fish, the more of them you have in an aquarium the more likely they are to show off their spawning behavior.
A word of caution on Otocinclus: Otocinclus are prone to starving to death. They are incredibly fussy eaters. They will quickly eat their way through the algae in the tank, then they will need something different to eat. I have had good success feeding my Ottos Repashy Soilent Green and also green beans from a can.
Otocinclus usually retail for between $2 and $4 per fish.
2. Black Mollies
Black Mollies, like other members of the Molly family, have fairly strong jaws, and an insatiable appetite. They spend almost their entire day eating or picking at the algae growing on plants, rocks, or the aquarium glass.
Black Mollies are one of my favorite fish of all time. Their deep black color contrasts incredibly against the greens of a planted tank.
These are livebearing fish, and members of the Poecilia genus of fish. Black Mollies are one of the few fish that actually choose to eat Black Beard Algae, which is one of the hardest algae to get rid of.
Being a livebearing fish, Black Molly populations can quickly grow, which can be considered either a pro or a con, depending on your long-term goals for your aquarium. If you are looking for a fish to breed for profit, Black Mollies might be an ideal choice.
Other members of the Molly family are pretty good at algae-eating too. Gold Mollies, Dalmatian Mollies, and Sailfin Mollies will all work just as well as Black Mollies when it comes to being on algae patrol.
3. Bristlenose Plecos
The Bristlenose Pleco is another stalwart of the freshwater aquarium. I have lost count of the number of talks I have given and articles I have written singing the praises of the Bristlnose Pleco.
For decades the Common Plecostomas was sold as the best algae eater for fish tanks, however, retailers neglected to tell buys that the Common Plecostomas can reach 20″ to 24″ (50cm to 60cm). The Bristlenose Pleco offers all of the algae-eating power of the Common Pleco, but only reaches about 5″ (12.5cm).
Bristlenose Plecos spend all day, every day stuck to the glass, or a piece of wood, or a rock, eating any algae they find. They will also quickly vacuum up any uneaten food that finds its way to the aquarium substrate.
Bristlenose Plecos are extremely placid and won’t bother any other fish in the tank, plus, as an added bonus, they are one of the easiest, non-livebearing, fish in the hobby to breed. As the old adage goes add water, will breed!
Over the years, some very talented breeders have selectively bred their Bristlenose Plecos to the point where we can now get albinos, orange, red, and super red Bristlnose Plecos, plus a selection of long-finned varieties.
4. Twig/Whiptail Catfish
Whiptail or Farlowella Catfish have been in the hobby for a long time, but have really seen their popularity rise in recent years.
Whiptail Catfish are found throughout much of the Orinoco River basin in South America where they inhabit slower flowing rivers and streams, often choosing to live in areas where there is ample vegetation both in the water and overhanging from the river bank.
Whiptail Catfish prefer to eat either brown, diatom, or soft green algae. They spend their entire day suckered onto either the glass or decorations within the tank.
Although males in spawning mode can become a little territorial, these fish are essentially a peaceful species of fish that fit well into a community aquarium with other peaceful fish. Tankmates could include Neon Tetras, Dwarf Cichlids, such as German Blue Rams or Apistogramas, and Angelfish.
Whiptail Catfish are relatively easy to breed, and there are many accounts of fish keepers finding their Whiptails have spawned in the community aquarium. Personally, I have managed to get them to spawn in my community tank, but sadly the fry always seem to get eaten.
If you want to try an algae eater that not everyone else has, give the Whiptail Catfish a go.
5. Siamese Algae Eater
Siamese Algae Eaters, which are sometimes referred to simply as SAEs, are extremely popular in the hobby and they are generally available at every local fish store across the country.
These are peaceful fish who spend much of their day scavenging for food along the bottom of the aquarium.
Siamese Algae Eaters are the fish for anyone with either Hair Algae or Black Beard Algae. There are many aquarium plant vendors up and down the country who keep Siamese Algae Eaters in their plant tanks to remove all traces of algae before they are shipped off to customers.
I currently have 17 Siamese Algae Eaters cross the tanks in my fish room as they are experts in keeping the tanks spotlessly clean.
Siamese Algae Eaters grow to about 6″ (15cm) in length, and their appetite for algae is definitely greater when they are smaller. Adult SAEs tend to eat more pellets foods such as Bug Bites or Vibra Bites.
Caution should be exercised when buying Siamese Algae Eaters as they can easily be confused with Chinese Algae Eaters, which tend to be larger are far more boisterous. Chinese Algae Eaters have their place, but not necessarily in the general community aquarium.
6. Nerite Snails
Nerite Snails are the first non-fish species to make my list, and I love Nerite Snails because they are one of the very few species in the hobby that will eat green spot algae.
Green spot algae is notoriously hard to remove, as anyone who has tried to get it off their aquarium glass will confirm. Nerite Snails has specially adapted mouth parts that have evolved to scrape the Green Spot Algae away.
Many fishkeepers shy away from snails fearing they will eat all the plants in the tank and multiply until there are thousands of snails. The good news is, Nerite Snails do neither.
Nerite Snails don’t eat plants. You can safely keep them in your planted tank without fear of returning to a tank full of nothing but plant stumps.
Also, to successfully complete their life cycle, Nertie Snail babies have to pass through a stage that requires brackish (slightly salty) water. They can not complete their lifecycle if they live solely in freshwater, meaning the number of Nerite Snails in your tank will never increase.
There is one downside to the Nerite Snail, however. Whilst they can not multiply in freshwater, they can lay eggs. Eggs that will never hatch. These are small and white and look like someone has put grains of salt over every surface in your aquarium.
You just have to decide which you like least, the look of the Green Spot Algae or the look of the Nerite Snail Eggs everywhere!
7. Rosy Barbs
Rosy Barbs, along with one or two other members of the Barb family, seem to enjoy some of the stringier algae such as Hair Algae, Black Bear Algae, and Staghorn Algae.
Rosy Barbs do not tend to eat huge mouthfuls of algae, but rather they pick at it constantly, eating small quantities, but eating it nevertheless. Rosy Barbs work really well as a preventative measure rather than a remedy to a heavy algae-infested tank.
Rosy Barbs are a peaceful species of fish that grows to around 3″ (7.5cm) long. They do best when kept in large groups (6 as a minimum, but more is better) and they will school back and forth across the aquarium.
Rosy Barbs have been selectively bred over the years, and they are now available in the long-finned form, which looks stunning, and as a Glofish, which I personally am not a massive fan of.
8. Florida Flag Fish
The Florida Flag Fish which is also often called the American Flag Fish is probably one of the most prolific algae eaters. This fish has a mouth that has evolved to rip algae from rocks, wood, and decorations.
Florida Flag Fish (Jordanella floridae) are members of the Killifish family and they are native to Florida. They get their common name because the males have red stripes across their bodies, with a gold, spotted patch on their shoulder, all of which resembles the American flag.
The Florida Flag Fish seems to actively enjoy eating the hair algae and will choose to eat Black Beard Algae and Hair Algae. One downside with the Florida Flag Fish is that whilst it doesn’t actively eat plants, it can end up damaging them in its pursuit of algae.
This fish works really well in unheated tanks and it can handle living with faster and rougher tank mates, making it ideal for aquariums where other algae eaters may be considered too delicate.
Florida Flag Fish can become aggressive during spawning, and they are known jumpers, so don’t be tempted to keep them in an open-top, rimless tank. They will end up on the floor.
9. Reticulated Hillstream Loach
The Reticulated Hillstream Loach is one of the oddest looking sucker fish in the hobby. They are often described as being like miniature stingrays. These small algae munchers only grow to around 3″ (7.5cm) long, but they have a never-ending appetite for algae that grows on flat surfaces such as green algae and brown diatom algae.
Reticulated Hillstream Loaches are surprisingly easy to breed at home, which can add another dimension to keeping them.
Reticulated Hillstream Loaches originate in tropical regions of Vietnam, Laos, and Cambodia, where they tend to live in fast-flowing rivers and streams, often in white water areas. In their natural habitat, they cling to rocks and pieces of wood, feasting on the algae they find.
They are a hardy species of fish that can handle a wide range of temperatures and pH.
Whilst Reticulated Hillstream Loaches would be considered peaceful fish, they can occasionally be aggressive towards other Hillstream Loaches. In my experience, they are best kept either as a single specimen or in a group of 3 or more, reducing the chance of one fish bullying another.
It is important this fish isn’t left to only scavenge algae. They will also need to be fed a proper diet, with Repashy being an ideal food.
10. Rubber Lip Pleco
The Rubber Lip Pleco (L187b), which is also known as the Bulldog Pleco, is another algae eater that originates in fast-flowing rivers and streams, eating algae growing on the rounded boulders and rocks it lives with.
Whilst the Rubber Lip Pleco comes from highly oxygenated, clear waters, it is a hardy and adaptable fish that can tolerate many different water conditions providing the extremes are avoided.
The Rubber Lip Pleco grows to about 3.5″ to 4″ (9cm to 10cm) and is a peaceful fish that fits well into most community aquarium setups.
Bright lighting should be used with the Rubber Lip Pleco to promote algae growth, although they will appreciate the addition of gel foods such as Repashy and lots of live or frozen bloodworms, daphnia, and brine shrimp.
Whilst the Rubber Lip Pleco is rarely bred in the home aquariums, occasional spawnings do happen. I suspect if you were to put some effort into a dedicated breeding setup, the Rubber Lip Pleco could be bred at home.
11. Rabbit Snail
Rabbit Snails, which are so named because of their very rabbit-like faces, are an active species of snail that spends huge parts of its day wandering around the aquarium looking for food. They will root out and eat any food that finds its way between rocks, into clumps of plants, or behind the aquarium filter.
Rabbit snails are fairly good algae eaters that graze rocks, wood, and the aquarium glass. Their diet does however need supplementing with algae wafers or a gel food like Repashy.
Rabbit snails are completely safe in planted tanks, although they will quickly devour any dead and dying leaves and plant stems they come across. Rabbit Snails will take little to no interest in your aquarium fish, making them suitable for just about any community aquarium.
Tankmates that might pick at the antenna, such a Bettas, should be avoided otherwise the stress of constantly being picked at may lead to the death of your Rabbit Snail.
Rabbit Snails, which grow to around 3″ to 5″ (7.5cm to 12.5cm) come in a variety of colors including orange, yellow, gold, spotted, black, and brown.
Rabbit Snails will breed in the aquarium, however, they reproduce very slowly, depositing only 2 or 3 eggs at a time.
12. African Cichlids
Whilst I agree it is a bit of a generalization to just list ‘African Cichlids’ as an algae eater, many, many of the species of fish that we call African Cichlids eat algae.
Many of the fish from Lake Malawi and Lake Tanganyika specialize in picking algae from rocks. They spend all day grazing. Members of the Mbuna and Labeotropheus are especially well known for their algae eating.
In truth, African Cichlids are not really suitable for the community aquarium, but rather need to be kept in a dedicated tank filled with their own kind.
13. Amano Shrimp
Amano Shrimp are probably one of the most useful members of the shrimp family when it comes to eating algae.
Amano Shrimp are named after the world’s most celebrated aquascaper, Takeshi Amano, who famously used them in almost all of his mammoth aquascapes.
Amano Shrimp are one of the few species in the hobby that will eat Black Beard Algae. Whilst Amano Shrimp won’t provide much relief from a major outbreak of Black Beard Algae, they are great at eating the starter tufts that form before an outbreak.
As such, Amano Shrimp should be added to an aquarium, especially a planted aquarium, before an outbreak of Black Beard Algae starts to take over.
These see-through shrimp not only eat the starts of Black Beard Algae, but they will also eat uneaten food they come across whilst wandering around the tank.
Amano Shrimp live for many years in the home aquarium. I have a group of half a dozen Amano Shrimp in one of my tanks that have been in there for 5 years. Unlike Red Cherry Shrimp, Amano Shrimp won’t reproduce in your aquarium as they require Brackish water to reproduce.
Be aware, some larger species of fish will happily eat Amano Shrimp, although they will be fine in the general community tank with Tetras and Guppies, etc.
14. Ramshorn Snails
I think Ramshorn Snails are one of my favorite species of snail to keep. They are the snail that gives all other snails a bad name because of the rapid pace at which they reproduce. However, the truth is, Ramshorn Snails only reproduce to the amount of food available for them to eat.
Ramshorn Snails live for 1 to 2 years and grow up to 1″ (2.5cm), although they rarely reach this size in the aquarium. They are available in a wide selection of both shell and flesh colors.
Ramshorn Snails eat many different forms of algae, but they also quickly consume both uneaten fish food and fish poop, making them the ideal clean-up crew.
These snails are completely plant-safe. I currently keep Ramshorn Snails in almost all my planted aquariums, without any issues. They will however eat dead and decaying plant leaves and stems.
Ramshorn Snails reproduce very quickly, meaning you may soon have more than you want. You could consider selling the excess on eBay or using them as live food for pufferfish.
15. Chinese Algae Eater
Chinese Algae Eaters originate from South East Asia where they inhabit a wide range of rivers and streams in the Mekong Basin.
These slender fish are often sold as Siamese Algae Eaters. Chinese Algae Eaters are however larger and more aggressive than Siamese Algae Eaters and are far less suitable for the community aquarium.
Chinese Algae Eaters are good algae eaters, although they eat less algae as they age. Their preference is for the flat algae such as green and brown diatom algae
In my experience, Chinese Algae Eaters are more suited to the larger community tank, possible with larger cichlids like Oscars as well as Silver Dollars, Tinfoil Barbs, and Green Terrors.
It should be noted that Chinese Algae Eaters have a tendency to suck the slim coat from other fish in the tank, which can place excess stress upon that fish.
Through selective breeding, the Chinese Algae Eater is currently available in a number of color forms including gold, marble, albino, and leucistic forms.
16. Red Cherry Shrimp
Red Cherry Shrimp have seen a surge in popularity over the last 10 years or so. They were once unheard of, but are now a mainstay of aquariums all over the world.
One Red Cherry Shrimp doesn’t eat very much algae, but when you have an army of them, they can make a real difference. Providing you set the environment up properly, meaning there are plenty of tiny hiding spaces, your Red Cherry Shrimp population will boom!
Red Cherry Shrimp not only eat algae, but they also feed on fish poop and any leftover fish food.
Red Cherry Shrimp grow to around 1.5″ (4cm) long and have been bred into a wide variety of colors including blue, orange, yellow, and black.
Whilst many hobbyists realize fish can be bred and sold for a profit, not so many people know that Red Cherry Shrimp can be bred for profit too. Half a dozen Red Cherry Shrimp can become hundreds in just a few weeks.
If you are planning to keep a group of Red Chery Shrimp to keep your tank clear of algae, remember that any fish with a mouth large enough to fit a Red Cherry Shrimp in its mouth will probably eat them.
17. Flying Fox
The Flying Fox, which is sometimes referred to as the Siamese Flying Fox, comes from fast-flowing, freshwater rivers and streams in Borneo, Java, and Sumatra in Southeast Asia. Flying Fox’s are often confused with the Siamese Algae Eater.
Flying Fox’s are bottom dwellers that are well-known for their algae-eating appetite. They are reputed to eat Black Beard Algae, although I haven’t seen my own Flying Fox eat Black Beard Algae.
Whilst Flying Fox’s can reach 6″ (15cm), it is more usual in captivity that they grow to around 4.75″ (12cm).
Although these fish do eat a lot of algae, they also want other foods to give them a balanced diet. Feeding live or frozen bloodworms, brine shrimp and daphnia will help provide all the vitamins and minerals they need.
In my experience, Flying Fox’s are best kept alone as they can be aggressive to one another. Tankmates can include Tetras like Neon Tetras, Rasboras, Angelfish, and Gouramis like Three Spot Gouramis or Dwarf Gouramis.
18. Panda Garra
Panda Garra are probably the most attractive member of the Garra family. They were only introduced to the hobby around 15 years ago, but since then they have developed a large following.
Panda Garra have modified lower lips that form a disc-like suction pad helping them stick firmly to rocks and boulders in their native waterways.
These fish grow to around 3″ to 3.5″ (7.5cm to 9cm) and have long, slender bodies designed to withstand the fast-flowing rivers and streams they naturally inhabit. The ideal setup for a Panda Garra includes lots of rocks and pieces of wood with a gravel substrate. Aquarium turnover should be 8 to 10 times per hour.
Whilst Panda Garra eat a lot of algae, they are not exclusively herbivore and they appreciate meaty foods such as bloodworms and daphnia.
Sadly, these attractive fish do lose their color as they age.
19. Mystery Snails
Mystery Snails are probably the largest freshwater snail in the hobby. Mystery Snails, which are also sometimes called Apple Snails, grow to around the size of a golf ball.
If there is one major benefit to Mystery Snails, apart from their insatiable appetite for algae, it is that they need to leave the water to reproduce, meaning if you want to keep a snail, but don’t like the thought of them taking over your entire tank, the Mystery Snail might be for you.
Mystery Snails will eat algae from the decorations in your tank, as well as from the glass and plant leaves. Mystery Snails won’t eat live plants, but they will eat dead and decaying plant matter.
Over the last few years, a number of talented and dedicated breeders have selectively bred Mystery Snails to bring us a wide selection of colors, meaning we can have almost as much color and variety from our Mystery Snails as we can from our fish.
Whilst Mystery Snails will spend hours eating algae, they should also be offered commercial algae wafers as well as sinking pellets like Bug Bites. I also feed my Mystery Snails frozen bloodworms and daphnia, just to give them access to vitamins and minerals that otherwise might be missing from their diet.
20. Crossocheilus Reticulatus
The Crossocheilus reticulatus makes an excellent alternative to Siamese Algae Eaters or Flying Fox’s, providing you can find them in your local fish store.
Crossocheilus reticulatus originate from the Mekong Basin in eastern Thailand, Cambodia, Laos, Vietnam, and southern China (Yunnan province). In their natural habitat, Crossocheilus reticulatus live in fast-flowing rivers and streams where algae and aufwuchs grow on the rocks and boulders.
This is peaceful species of fish that will fit in well in most community aquariums, although it is best kept in small schools of 4 or more, otherwise, it may prove to be shy and skittish.
21. Malaysian Trumpet Snails
Malaysian Trumpet Snails are prolific algae eaters that come out at night to munch on any algae they can find before returning to the substrate to hide out of sight during the day.
Not only do Malaysian Trumpet Snails eat algae, but they will also eat any uneaten fish food that makes its way between rocks, into plants, or behind decorations. These snails will also break down fish poop and churn the substrate preventing the build-up of hydrogen sulphide gas.
Malaysian Trumpet Snails are essentially livebearers, meaning they can reproduce quickly, and numbers can spiral out of control.
However, snails technically only multiply to the amount of food available, meaning if you tank has 500 snails, it is probably because there is enough food to support 500 snails.
There is a wide range of algae eaters available in the hobby, and the answer to your problem might not lay with a single species.
In a number of my planted display tanks, I keep shrimp, snails, and algae-eating fish like Bristlenose Plecos. I have found prevention is better than cure, especially when it comes to tricky algae to eradicate like Black Beard Algae or Hair Algae. As such I like to put lots of shrimp in my tanks from day one.