Over time, your aquarium is going to build algae. Algae are like underwater weeds. It isn’t necessarily going to hurt anything, but it can overwhelm the balanced ecosystem in your tank and can make the whole thing look gross and unclean. There are ways to clean the tank or filter the water, but what if you could get a fish that would just eat away that algae without you having to do anything? Well, that would make life a lot easier, wouldn’t it?
What are the best algae eating fish for you? While certain breeds like the Siamese algae eater and the Otocinclus catfish are trendy and quite hardy, you’ll want to consider the conditions of your tank setup before selecting an algae eater. Tank size, water temperature, and water pH are all among the things you’ll want to take into account.
There are tons of great algae eaters out there that can help eliminate or manage an algae problem. Selecting the right one for your tank is critical to your success. You don’t want to create more problems than you solve or spend money on a fish that can’t survive in your aquarium. Follow this guide, and we’ll help you select the right algae eater or eaters for your setup.
What to Consider in an Algae Eating Fish
Before you head out to your local pet store and pick up the first algae eater you find, you want to make sure that you’re selecting something that will fit the needs of your tank. There are quite a few things to take into account here. You want to make sure that the algae eater you buy is going to eat the type of algae you’re having a problem with. You’ll also want to check that your tank conditions are compatible.
Will it Fix the Problem?
Presumably, you’re buying an algae eater because you’ve got an algae problem that you need to be taken care of. You may be surprised to learn that there are many types of algae, and most algae eaters will not eat all the types.
In fact, rather than getting a single algae eater, you’re likely going to want a team of algae eaters to cover the various common types of algae and the different surfaces it can grow on. Some algae eaters will be better at covering flat surfaces, while others will be better at getting into smaller nooks and crannies. Making sure the different areas of your tank are covered from multiple types of algae will help prevent algae infestations.
Here’s a breakdown of the different types of algae:
- Hair algae – Hair algae forms thin wispy strands of green threads. These strands feel like wet hair to the touch and can be difficult to remove completely. Hair algae will mainly anchor to plants but may spread to other surfaces.
- Brown algae – What starts as a brown dusting over the surfaces of your tank can turn into a thick coating of brown slime within days. Brown algae can get nutrients from photosynthesis and chemicals such as silicate, phosphorus, and nitrates. This means that brown algae can thrive even in low light environments.
- Blue-green algae – Not actually an alga, but photosynthesizing aquatic cyanobacteria. Blue-green algae have a blue-green color and will grow on the surface of the water or build in layers against the glass. Think about your typical pond scum. Green algae fix nitrogen, eventually depleting the nitrogen in the water, which will negatively affect your fish and any aquatic plants.
- Black beard algae – Brown beard algae has a brown or dark purple appearance and grows in dense patches (which look like patches of beard). This alga thrives on hard surfaces, like the side of your tank, but can also grow on slow-moving plants and another tank décor.
- Green spot algae – Appearing as small, hard green dots, if allowed to thrive, these will spread along with the glass, décor, and plants in your tank. They’ll expand beyond dots into a full coating.
- Green algae – If the water in your fish tank suddenly turns a pea soup green color, you’ve got green algae. Green algae are photosynthesizing single-celled organisms. This allows it to reproduce and spread very quickly. Green algae make your tank look awful and can potentially be harmful to your fish.
Will it Survive in my Tank?
You’ll need to make sure that any algae eaters you buy are compatible with the environment of your tank. Aquatic creatures suitable for aquariums can come from different places all over the world. Freshwater conditions can vary wildly. You’ll need to either buy something that will thrive in your tank as is or change conditions in your tank to allow for the algae eater you want.
Here’s what you need to watch out for:
- Water Temperature
- Water Acidity
- Tank Size
Algae Eating Fish
Fish are the most obvious choice for algae eaters. These are what you’re likely to find in your local pet store. Fish are versatile, come in all different sizes, and some are just gorgeous—adding both form and function to your tank.
1. Siamese Algae Eater
(lat. Gyrinocheilus aymonieri)
Siamese algae eaters are marked by the black stripe running down their length. They can be quite active, zipping from one end of the tank to the other, which can make them quite fun to have around. They’re also on the bigger size as far as algae eaters go, growing up to seven inches in length, so they’ll be fairly prominent in the tank.
Living longer than you might expect, Siamese algae eaters can live up to ten years. They’ll lose their appetite for algae as they grow older, unfortunately. You will likely need to supplement their diet with algae wafers or flakes. They are extremely popular due to the fact that they’ll eat many types of algae, including black beard algae, which many other algae eaters won’t touch.
| Siamese Algae Eater Requirements | |
| Algae target | Black beard algae, hair algae, green algae, |
| Water Temperature | 75 – 79°F (24°C – 26°C) |
| Water Acidity | 6 – 8 pH |
| Tank Size | <40 gallons (<150 liters) |
2. Bristlenose Pleco
(lat. Ancistrus)
Bristlenose Plecos have a unique and unusual appearance, with a bright, spotted pattern, fleshy tentacles, and whiskers. These are a popular choice as a smaller variety of catfish, growing to about five inches. They are docile and are well suited to community tanks, where they’re unlikely to cause problems with other fish.
Additionally, they will vacuum algae from the water, cleaning constantly as they subsist on mostly algae. Bristlenose Pleco will actively dig through the substrate looking for algae rather than passively waiting to find it. This can help prevent algae from building up in the first place and can help with maintaining a perfectly clean tank.
| Bristlenose Pleco Requirements | |
| Algae target | Brown algae, hair algae, green algae, green spot algae |
| Water Temperature | 73 – 81°F (23°C – 27°C) |
| Water Acidity | 5.8 – 7.8 pH |
| Tank Size | <40 gallons (<150 liters) |
3. Otocinclus Catfish – so called “dwarf sucker” or “otos”
(lat. Otocinclus)
Otocinclus Catfish are small fish, growing up to a maximum of two inches. They are similar in appearance to the Siamese algae eater and will dart back and forth across the tank in a similar way. Otocinclus Catfish is incredibly good-natured and can be purchased in any quantity without fear of disrupting community tanks.
These small algae eaters are great if you want your tank cleaners to do their job without necessarily adding prominently to the aesthetic of the tank. They are great at getting into small spaces. They’ll eat algae off the glass, but really prefer to eat off plants.
| Otocinclus Catfish Requirements | |
| Algae target | Brown algae, hair algae, green algae, |
| Water Temperature | 72 – 79°F (22°C – 26°C) |
| Water Acidity | 6.8 – 7.5 pH |
| Tank Size | Any size |
4. Twig Catfish
(lat. Farlowella acus)
The Twig catfish has a long body, elongated snout, and brown-green coloration resembling a twig. Twig catfish will lie motionless for long periods, suckering themselves to a log or stone, totally dedicated to camouflage. They will only occasionally release themselves to gobble up bits of algae or to move to a new position.
If you’re looking for a tank cleaner that will do its job without drawing a lot of attention, there’s no more subtle option than a Twig catfish. These fish are non-aggressive to their own detriment. If they’re placed in a tank that’s too crowded, they’ll easily be outcompeted for food. They also require pristine water conditions to survive but can survive up to ten years if the proper conditions are maintained.
| Twig Catfish Requirements | |
| Algae target | Brown algae, green algae, |
| Water Temperature | 75 – 79°F (24°C – 26°C) |
| Water Acidity | 6.0 – 7.0 pH |
| Tank Size | <20 gallons ( <76 liters) |
5. Chinese Algae Eater
(lat. Gyrinocheilus aymonieri)
Chinese algae eaters come in a wide variety of colors and patterns, though you’re most likely to find them as a golden yellow color when in tanks. They’re bottom feeders and will clean algae off the substrate and low-lying structures or plants.
Similar to Siamese algae eaters, Chinese algae eaters consume algae voraciously in their youth but slow down as they gain maturity. The breed is valued for its hardiness, as it can adapt to a wide array of tank conditions. They’ll be most at ease if you provide a few shelters for them to spend time in. Chinese algae eaters can also get quite aggressive and are not well-suited for community tanks.
| Chinese Algae Eater Requirements | |
| Algae target | Brown algae, green algae, |
| Water Temperature | 75 – 80°F (24°C – 27°C) |
| Water Acidity | 5.8 – 8.0 pH |
| Tank Size | <30 gallons ( <114 liters) |
6. Reticulated Hillstream Loach
(lat. Sewellia lineolata)
Reticulated Hillstream Loaches are adapted to swim against fast-moving Asian streams. They have flat, streamlined bodies, covered in beautifully intricate patterns. These fish will do best with heavy water flow.
Hillstream loaches are incredibly effective at cleaning the surface of the glass and other large flat surfaces. They are grazers, and you may have trouble getting to accept other types of food. Hillstream loaches can be so effective at eliminating algae that you may need to actively cultivate it just to keep them alive.
| Reticulated Hillstream Loach Requirements | |
| Algae target | Green spot algae, green algae, |
| Water Temperature | 65 – 75°F (18.3°C – 24°C) |
| Water Acidity | 6.5 – 7.5 pH |
| Tank Size | <30 gallons ( <114 liters) |
7. Corydora
(lat. Corydoras sterbai)
Corydoras are small, colorful, and active bottom-feeders. Corydoras do best in schools of six or more. It can be quite interesting to watch them move across the tank as a single unit. They are an attractive but unassuming addition to any tank. They enjoy tanks with lots of vegetation and hiding places to rest.
These fish will constantly sweep the bottom of the tank, searching for algae or other morsels. Their active approach to algae-eating will result in a clean tank. Corydoras require minimal upkeep and are quite popular with beginners.
| Corydora Requirements | |
| Algae target | Green spot algae, green algae, |
| Water Temperature | 72 – 78°F (22°C – 25.5°C) |
| Water Acidity | 7.0 – 7.8 pH |
| Tank Size | Any size |
8. Siamese Flying Fox
(lat. Crossocheilus oblongus)
Frequently confused for, and even often sold as, Siamese Algae Eaters—Siamese Flying Foxes, are modest algae eaters which lack many of the benefits of their cousins. Unlike Siamese Algae Eaters, Flying Foxes won’t touch Black Beard Algae and consume significantly fewer algae overall. You can distinguish Flying Foxes from Siamese Algae Eaters by the orange stripe along their bodies and their much darker fins.
That being said, Siamese Flying Foxes are algae eaters and will help keep down algae problems in your tank. Just don’t expect them to go after Black Beard Algae or to consume as much as Siamese Algae Eaters. They’re also quite active and can add some life to a quiet tank.
| Siamese Flying Fox Requirements | |
| Algae target | Brown algae, green algae, |
| Water Temperature | 75 – 79°F (24°C – 26°C) |
| Water Acidity | 6.0 – 8.0 pH |
| Tank Size | <40 gallons (<150 liters) |
9. American Flagfish
(lat. Jordanella Floridae)
Coming in a variety of colors and patterns, some varieties have a mixture of red, creamy white and deep green scales. The red scales line up in horizontal lines, approximating the Star-Spangled Banner, leading to the name of this fish.
These tropical Killifish are a gorgeous addition to any tank, but they also can be quite voracious algae eaters. They seem to be somewhat temperamental in this regard. Some tank owners report them being insatiable when it comes to algae, while others have a hard time getting them to touch the stuff.
| American Flagfish Requirements | |
| Algae target | Hair algae, green algae, |
| Water Temperature | 66 – 72°F (18.9°C – 22°C) |
| Water Acidity | 6.7 – 8.2 pH |
| Tank Size | <20 gallons (<75 liters) |
10. Molly Fish
(lat. Poecilia Sphenops)
Molly Fish or Mollies are a popular choice for newcomers to the hobby. There are over thirty varieties of Molly fish in a variety of colors, patterns, and forms. These include the Black Molly Fish, Sailfin Molly, Lyretail Molly, Dalmatian Molly, and Balloon Molly. Interestingly, Mollies are livebearers, meaning that they don’t lay eggs to reproduce.
Molly Fish will do best if you keep them in groups of four or more and give them plenty of foliage to hide in. They’re a school fish, and you’ll enjoy watching them swim around together. Mollies generally will only eat algae when underfed but can be coaxed into eating Blue-Green Algae, which can be particularly tricky to get rid of. Probably not the best algae eater out there, but potentially helpful and beautiful fish.
| Molly Fish Requirements | |
| Algae target | Brown algae, blue-green algae, |
| Water Temperature | 72 – 78°F (22°C – 25.6°C) |
| Water Acidity | 6.7 – 8.5 pH |
| Tank Size | <10 gallons (<40 liters) |
Algae Eating Snails
Fish aren’t the only algae-eaters out there. Snails can be quite effective algae-eaters. They maintain a low-profile and are generally pretty hardy. Snails eat some types of algae that very few fish will touch, such as blue-green algae or green spot algae. Snails can help round out any algae eating squad.
11. Nerite Snail
(lat. Neritina natalensis)
Nerite Snails are among the most popular freshwater aquarium snails. Known for being diligent tank cleaners, Nerite Snails do a great job with flat surfaces such as tank sides and substrate. Coming in a number of varieties, including Black Racer, Tiger, Zebra, Olive, and Horned, Nerite snails are available in a wide variety of colors and patterns.
One huge benefit of Nerite Snails is that they cannot reproduce in freshwater. This will prevent them from overwhelming your tank. However, they may still produce hard, white eggs that will need to be scratched off surfaces inside the tank.
| Nerite Snail Requirements | |
| Algae target | Brown algae, hair algae, green spot algae, |
| Water Temperature | 72 – 78°F (22°C – 25.6°C) |
| Water Acidity | 7.0 – 8.2 pH |
| Tank Size | Any size |
12. Malaysian Trumpet Snail
(lat. Red-rimmed melania)
Malaysian Trumpet Snails are tiny, with long shells that spiral to a point. They will bury themselves completely in the substrate during the day, coming out only at night to feed and roam around. This makes Malaysian Trumpets desirable for hobbyists who want the benefits of having snails, but don’t enjoy the aesthetic of snails in the tank.
Considered a pest by some because of their ability to reproduce rapidly, these snails will quickly spread through your tank. Because they reproduce asexually, even one can spawn a whole colony. Although they aren’t incredible algae eaters, Malaysian Trumpet Snails are quite good at consuming decaying plant bits or other debris. They’ll also keep your soil churned and rotated, allowing for essential nutrients to reach plant roots.
| Malaysian Trumpet Snail Requirements | |
| Algae target | Brown algae |
| Water Temperature | 72 – 78°F (22°C – 25.6°C) |
| Water Acidity | 7.0 – 8.2 pH |
| Tank Size | Any size |
13. Ramshorn Snail
(lat. Planorbarius Corneus)
Ramshorn Snails are some of the best looking of the snail varieties. They come in a number of different colors and patterns. They are quite large as snails go, growing up to two inches in length, making them a prominent part of the tank.
Ramshorns will eat soft algae as well as gobbling up dead or dying plant bits. This will keep the tank free from rotting plant parts, which can look ugly and lead to problems for other plants nearby. Like most types of snails, they reproduce like crazy and quickly take over a tank. They’re not going to hurt your fish or plants, so an overabundance might not be the worst thing.
They reproduce hermaphroditically, meaning that two members of the species from the same sex can reproduce. If you want to avoid a takeover, just get one. You can also control their numbers by limiting the amount you feed into the tank.
| Ramshorn Snail Requirements | |
| Algae target | Brown algae, green algae, |
| Water Temperature | 70 – 78°F (21°C – 25.6°C) |
| Water Acidity | 7.0 – 7.5 pH |
| Tank Size | Any size |
14. Mystery Apple Snail
(lat. Ampullariidae)
The Mystery Apple Snail is another colorful, attractive snail option. You can recognize a Mystery Apple Snail by its long eyestalks. The eyestalks will regrow completely if severed.
Mystery Apple Snails are prized for their ability to eat algae that many other fish won’t touch. Green spot algae and blue-green algae can be particularly difficult to get rid of. Blue-green algae can be especially problematic as it’s toxic to many fish. If you’ve got a problem with these algae, Mystery Apple Snails may be your best bet.
| Mystery Apple Snail Requirements | |
| Algae target | Brown algae, green algae, Blue-green algae green spot algae, |
| Water Temperature | 68 – 84°F (20°C – 28.9°C) |
| Water Acidity | 7.6 – 8.4 pH |
| Tank Size | Any size |
15. Rabbit Snail
(lat. Tylomelania)
Rabbit snails have long, cone-shaped shells with a grooved spiral pattern. They are typically about two inches long and will grow as they age. You can find them in several colors and varieties, including Yellow Poso Rabbit Snails, Yellow Spotted Rabbit Snails, White Spotted Rabbit Snails, Black Rabbit Snails, Orange Rabbit Snails, and Gold Rabbit Snails.
Like other breeds of freshwater snails, Rabbit snails are quite good at cleaning soft algae off the glass and substrate of aquarium tanks. They’re among the prettier snail varieties, and many people keep them for the appearance they add to the tank.
| Rabbit Snail Requirements | |
| Algae target | Brown algae, green algae, |
| Water Temperature | 76 – 84°F (24.4°C – 28.9°C) |
| Water Acidity | 7.2 – 7.5 pH |
| Tank Size | Any size |
More about snails wonderland in Fish Tank read here – Snails for Freshwater Fish Tanks.
Algae Eating Shrimp
Freshwater shrimp fill a niche that neither algae-eating fish or snails can quite fit. They’re quite adept at gobbling up hair algae, which some algae eating fish struggle with. They’re also quite good at using their arms to scrape algae out of places that fish and snails can’t get to. Odds are that to keep your tank fully clear of algae; you’ll want a mix of algae-eating fish, snails, and shrimp.
16. Red Cherry Shrimp
(lat. Neocaridina Davidi)
Cherry shrimp are small, usually bright red freshwater shrimp hailing from Thailand. They have a reputation for being excellent algae and will gobble up many types of algae. They don’t have as big of appetites as larger algae eating fish, but they make a great clean-up crew.
Generally, you’ll want to place about two to five shrimp per gallon of water in your tank. If they’re in a larger colony, they’ll feel more secure and will more confidently explore to dig up and eat bits of algae. Cherry shrimp are hardy and can thrive in a wide range of tank conditions.
| Cherry Shrimp Requirements | |
| Algae target | Brown algae, hair algae, green algae, |
| Water Temperature | 65 – 80°F (18.3°C – 26.7°C) |
| Water Acidity | 6.5 – 8.0 pH |
| Tank Size | Any size |
17. Amano Shrimp
(lat. Caridina Multidentata)
Behind Cherry Shrimp, Amano Shrimp undoubtedly take second place for the most popular freshwater shrimp. Amano shrimp can grow up to two inches and have grayish, translucent bodies. Making them much more understated than Cherry Shrimp. They will frantically race after food when feeding time comes, and you’ll be able to observe an interesting pecking order as the largest shrimp claim first dibs.
Amaro Shrimp are great if you want an algae eater that will get to work without being prominently displayed in the tank. Their colors can make them almost invisible and difficult to find within the tank. They are also absolutely relentless and will tirelessly hunt down bits of algae in your tank. You know that they’re getting a lot of the stuff if their bodies take on a green tinge.
| Amaro Shrimp Requirements | |
| Algae target | Brown algae, hair algae, green algae, |
| Water Temperature | 70 – 80°F (21°C – 26.7°C) |
| Water Acidity | 6.0 – 7.0 pH |
| Tank Size | <10 gallons (<40 liters) |
18. Ghost Shrimp
(lat. Palaemonetes paludosus)
Named for their fully translucent bodies, Ghost Shrimp can be a valuable addition to any freshwater tank. They are largely sought after for their clear bodies, which allow aquarium viewers to watch the food being processed and digested in real-time.
Like most freshwater shrimp, Ghost shrimp prefer to live among an abundance of plants where they can hide after molting their shells. Ghost shrimp will scuttle along the surface of the substrate of your tank hunting for algae they can devour. They’ll occasionally burrow themselves into the substrate, cleaning deeper down and allowing essential nutrients to more easily reach plant roots.
| Ghost Shrimp Requirements | |
| Algae target | Brown algae, hair algae, green algae, |
| Water Temperature | 65 – 82°F (18.3°C – 28°C) |
| Water Acidity | 7.0 – 8.0 pH |
| Tank Size | <10 gallons (<40 liters) |
19. Bamboo Shrimp
(lat. Atyopsis)
Native to southeast Asia, Bamboo Shrimp have a unique “woody” pattern to them, allowing them to disguise themselves as bamboo or driftwood in their natural habitats. Bamboo Shrimp are distinctive not only from their pattern but also the fan-like structures which they use to catch algae and other edible debris from the water to eat.
Bamboo Shrimp feed continually throughout the day and will position themselves facing the current, plucking bits of algae out of the water. They can be quite fun to watch. Oftentimes algae in your tank alone will not be enough for shrimp. You can crush an algae wafer into a fine powder and spread it through the tank to give them supplemental nutrition.
| Bamboo Shrimp Requirements | |
| Algae target | Brown algae, hair algae, green algae, |
| Water Temperature | 65 – 82°F (18.3°C – 28°C) |
| Water Acidity | 7.0 – 7.5 pH |
| Tank Size | <20 gallons (<76 liters) |
In the case you did not find your favorite algae eater above, you still have a chance by trying to control algae manually – the hard way. Check the next post, Easy and Fast Way to Clean Algae form your Fish Tank.
