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Best Algae Eaters

One of the most common problems in freshwater aquariums is an overabundance of algae. A little algae growth is normal but left unchecked these photosynthetic organisms can quickly take over your tank. Adding the best algae eaters to your aquatic community can help keep your aquarium clean the easy way!

Guide To Freshwater Algae Eaters

golden algae eater in a aquarium with anubias plant

Algae is a common problem in both new and mature aquariums. It’s completely normal to have to scrape algae growth off the sides of a tank, but it can be trickier to clean your substrate, equipment, live plants and decor. Algae eating invertebrates and fish tank cleaners can help alleviate the problem for you!

What Are Algae Eaters?

Algae eaters include a wide variety of fish, shrimp and snails that feed entirely or primarily on algae and other plant materials in an aquarium. Depending on the species, algae eaters may eat a broad swath or target a specific variety of algae. These aquatic organisms make a great option for community tanks of all sizes!

How Effective Are Algae Eating Fish And Invertebrates?

The effectiveness of your algae eaters will depend on:

  • Your aquarium, filtration and light set-ups
  • The types of algae and live plants in your tank
  • The type and number of algae eaters in your community aquarium

Some species like Siamese Algae Eaters, American Flag Fish and Amano Shrimp are champion algae eaters and can make a significant dent in a problem tank. Others like Plecostomus and their fellow catfish act as scavengers and clean up leftover food in addition to snacking on algae.

Hypostomus Plecostomus, bottom dweller cat fish or algae sucker, checking underwater rocks and caves

It’s often a good idea to have a couple types of algae eaters in your community. Consider getting a variety that is an algae-eating machine and then fill in the gaps with some scavengers and species that munch on decaying plant materials. This will allow you to strike a balance in your algae battles and help keep your tank cleaner.

How To Pick An Algae Eater For Your Tank

The best way to choose an algae eater for your tank is to look for one that fits in with your existing community. Pick a species or two that’s compatible with the other fish and invertebrates you have and that works with your aquarium’s size, temperature, pH, and water hardness.

Most algae eaters prefer densely planted tanks although some species do well in tanks without live plants. Your type of substrate matters, however.  Many algae eaters are bottom dwellers and prefer soft substrates like sand and fine gravel to the jagged and injury-causing pea-sized aquarium gravels.

Algae Eaters For New Aquariums Vs Mature Tanks

It’s usually a good idea to wait a few weeks before adding an algae eater to a new tank to give the filter time to cycle. While algae often blooms during the “new tank syndrome” stage, you don’t want to add an algae eater until things have settled and there’s an abundant and consistent source of food for them.

How To Clean a Fish Tank With Vinegar - Man using magnetic aquarium cleaner to clean aquarium.

Avoid adding species that feed on biofilm to a new or recently cycled tank. It takes a few months to develop a healthy matrix in a new tank and they will starve in the meantime. These species are best kept in mature aquariums with a healthy and balanced mix of biofilm and algae. I cover more about biofilms below.

If your tank frequently has problems with a specific type of algae then you can target it by choosing an algae eater that likes to snack on that type. This is a slow and gradual process and may take a few weeks to see a substantial difference. Not all types of algae are edible, however, so you may need to take other actions as well.

Types Of Freshwater Algae

Algae is the catch-all term for aquatic organisms that convert energy from the sun into food through photosynthesis. Algae may be single or multicellular organisms (seaweed is a type of algae) or grow as a biofilm in a protein matrix with bacteria and fungi. The types of algae you’re most likely to see in your tank include:

Hair Or Thread Algae

Hair or thread algae is a Filamentous species that forms soft green threads on live plants, decorations and on the surface of your substrate. It’s called hair algae because it’s long and feels like wet hair when you remove it. It’s a very fast-growing type of algae and is not easy to eradicate.

Common frog (Rana esculenta, Syn. Pelophylax esculentus) basking on a carpet of algae from filamentous algae

Causes

Hair algae is usually a problem in a tank that has too many nutrients building up in the water. Excess light shining in the tank or high iron levels can also cause a hair algae bloom. By the time the problem is addressed, your CO2 and nitrate levels have usually crashed too.

Options For Fixing A Hair Algae Problem

In addition to correcting your water chemistry and adjusting your lights, you might consider adding Amano Shrimp, Fancy Mollies, Siamese Algae Eaters, Mystery Apple Snails or American Flag Fish to your tank to help consume the problem weeds.

Brown Algae

There are two types of brown algae but one type, brown slime algae, only grows in saltwater environments. The brown algae growing in a freshwater tank is a type of diatom that can photosynthesize and convert energy from the silica, phosphorus and nitrates in your tank.

Brown algae starts as a dusting of yellow-brown or reddish-brown specks on your glass, substrate, live plants and decor. The “dust” feels a bit gritty when you rub it between your thumb and finger. Within a week the dust turns into a layer of brown slime that coats your entire tank.

Brown algae, fucus

Causes

Most of the time, a brown algae bloom means you have too many nutrients in your tank along with low oxygen levels and inadequate lighting. If you fix these problems the algae may clear up on its own. It can take a couple of months to clear up naturally.

Options For Dealing With Brown Algae

It’s very common to have problems with brown algae in a new aquarium, but it usually resolves once your tank has cycled. If you develop brown algae in a mature tank then you probably have a water quality problem. There are fish that eat brown algae so add Otocinclus Catfish or a Plecostomus to your tank to help prevent outbreaks.

Black Beard Algae (BBA)

Despite the name, black beard algae or BBA is actually a type of red algae from the Rhodophyta family. It forms clusters of slippery black or purplish threads on any of the hard surfaces in your tank and kind of resembles a patchy beard. This alga is the bane of aquarists with mature tanks! It’s incredibly hard to remove too.

This stuff grows on the glass, leaves of your plants, on bog and driftwood decorations and on your equipment. It’s not hard to scrape off your glass, but good luck with your plants and decor. I’ve pruned plants back rather than try to remove a heavy load of BBA. The only good thing is that it tends to be slow-growing so it doesn’t spread fast.

Causes

The most common reason for a BBA bloom is either inconsistent lighting or a combination of factors including inadequate circulation and low or unstable CO2 levels. You’ll often see BBA in mature tanks on slow-growing plants where it’s easily pruned away. If you see a sudden spike in BBA you should try to identify the problem.

Clearing Black Beard Algae From Your Tank

Once you’ve identified and fixed the problem that caused the algae to bloom you should mechanically remove as much of the BBA as you can from your equipment, plants and decor. Then control further outbreaks by adding Siamese Algae Eaters, Amano Shrimp or American Flag Fish to your tank.

Green Dust Algae (GDA)

There are many varieties of green algae and green dust algae or GDA is a term used for several slime-producing species. GDA appears as a layer of green slime on your glass, equipment, live plants, and substrate. Unlike green spot algae below, GDA doesn’t form in clusters but coats everything in the tank at the same time.

Causes

It’s commonly seen in new aquariums that don’t have an established bacterial base yet but occasionally pops up in mature tanks too. If you’ve just added a bunch of plants to your aquarium or pruned them you could see an outbreak of GDA. It often happens when there is an imbalance of CO2 and nutrients.

Cleaning Green Dust Algae From A Tank

Green Dust Algae in aquarium

You can easily wipe the green slime from your glass and equipment but this will actually cause the algae to release spores into your water and perpetuate the bloom. Alternatively, consider waiting it out for a month. That will naturally complete the algae’s life cycle.

Four weeks later remove as much water as possible, and then before you replace it wipe away as much of the slime as you can with a rag. Don’t let the mucus fall into the water still in your tank. Then refill your aquarium and add a Bristlenose Plecostomus to snack on the rest!

Green Spot Algae (GSA)

Green spot algae (Coleochaete orbicularis) or GSA is another species of green algae. GSA starts as tiny hard green dots on your aquarium’s glass, equipment, slow-growing plants and decor. If conditions in your tank are right the dots will start to expand until your tank is coated in algae.

Causes

GSA is often seen in newly-cycling tanks but usually only becomes a problem when there’s a nutrient imbalance, too much light or deficient CO2 for the live plants. GSA adheres tightly to your glass and decor and can be challenging to scrape off.

Fixing A Green Spot Algae Outbreak

In new tanks, you can often wait the problem out and clear the algae away once the tank has finished cycling. For an outbreak in a mature tank, you should check your phosphate levels and correct them with a phosphorus supplement if they are out of balance. Then wipe away the GSA and see if it reoccurs.

If that doesn’t fix the problem try adding more CO2 to your tank and reduce your aquarium lights. Nerite Snails can help keep it in check too because they are great at scraping GSA from glass, plants, and decorations.

Green Water Algae

Have you ever had an algae bloom that turned your tank water into something resembling pea soup? Then you’ll be familiar with a green water algae outbreak. This unicellular algae from the Euglena family is tough to beat back because it replicates really fast! You can do a massive water change and be back to soup in 24 hours.

Green water algae won’t hurt your fish but it’ll reduce the amount of light your plants receive. Plus, you won’t be able to enjoy watching your aquarium. This is an especially common problem in new tanks that are cycling and recently planted tanks.

Causes

Green water algae blooms are usually triggered by an increase in the light and nutrients in your tank. Maybe sunlight is hitting your tank or you’re over-feeding or just added plant fertilizer. If the plants don’t use all these extra nutrients they can build up and the algae floating in your water goes into a feeding frenzy.

Tackling A Green Water Algae Bloom

It can be a real pain to deal with a tank that has a green water algae outbreak because you can’t just fix the problem by stabilizing your water chemistry. The algae reproduces too quickly for water changes to have much effect.

It’s best to prevent green water algae blooms by using a light timer and blocking sunlight from your aquarium. If you keep up on your water changes and filter maintenance you hopefully won’t have ammonia spikes. Adding snails and shrimp to the tank can consume the algae early on before it can cause the soup to form.

Consider Adding A UV Sterilizer

If you can’t get things under control by fixing the excess light and nutrient problem then you’ll have to resort to killing the algae. You can do this by entirely blacking out your tank for a few days, similar to treating blue-green algae. Of course, this might kill your live plants as well.

Aquaterrarium, UV sterilizer

A better option is to get a UV sterilizer or invest in a high-quality filtration system that includes a UV-sanitizing stage. Passing your aquarium water through a filter like this will kill the algae cells and quickly clear your water. These devices also work great for killing microorganisms that could harm your fish or invertebrates!

Blue Green Algae (BGA)

The final type of algae you often see in freshwater tanks is an oddball. Blue-green algae or BGA is not a true algae but a type of photosynthesizing and nitrogen-fixing microorganism called Cyanobacteria. It forms a thick blue-green colored mat of algae on your glass, substrate and equipment.

You’ll usually see the heaviest accumulation on the parts of your tank that get the most light, such as the front of the tank or the part closest to a window. BGA feeds on the organic waste products in your tank and is a sign of poor water quality.

Causes

BGA usually occurs in tanks that are overfed with infrequent water changes and too much light. The out-of-balance water chemistry sparks the algae bloom and the BGA rapidly takes over. It’s hard to eradicate because it grows so quickly, doubling in number in as little as 20 minutes!

How To Eliminate Blue Green Algae

The first thing you should do is test your aquarium water and correct your water chemistry. Remove as much of the BGA from your tank as you can. You may even be able to lift or vacuum it from your substrate. Adding more fast-growing plants like hornwort can help because they will compete with the BGA for nutrients.

Next, assess your aquarium lights and filtration. If BGA is forming in parts of your tank without adequate water circulation consider adding another filter to improve things. A good 3-stage filter and reduced lighting may be enough to turn the outbreak around.

If that doesn’t work, your final options are to completely black-out your aquarium for a week to “starve” the BGA, or to dose your tank with antibiotics like Maracyn. Unfortunately, there are no algae eaters that consume BGA so we don’t have any way to naturally control an outbreak.

Type of Algae (Family) Appearance Causes Solutions Algae Eaters
Hair/Thread
(Filamentous)
Fine, long green threads on live aquarium plants and substrate Imbalanced nutrients and/or too much iron

Low CO2 and/or nitrate levels

Too much light

Test and improve nutrient balance

Increase CO2

Reduce light levels

Amano Shrimp

Fancy Mollies

Siamese Algae Eaters

American Flag Fish

Mystery Snail

Brown (Diatom) Dusting or spots of brown algae that quickly spread into a slimy mat coating everything in the tank Inadequate light

Poor water quality

Low oxygen levels

Mechanical removal

Add or increase filtration

Increase frequency and amount of water changes

Improved tank lighting

Increase water oxygenation

Otocinclus Catfish

Plecostomus

Black Beard (Rhodophyta) Brown, black or purple-looking clusters of “hair” that look like a bread growing on glass, equipment, live plants and/or decor Low or unstable CO2 levels

Inconsistent levels of light

Poor water circulation

Mechanical removal when possible

Increase CO2 levels

Improve filtration and circulation

Adjust lighting conditions

Siamese Algae Eater

Amano Shrimp

America Flag Fish

Green Dust A fine layer of green slime that coats the glass, equipment, live plants and substrate New Tank Syndrome

Imbalance of nutrients and CO2

Wait it out for 4 weeks, then clean the tank Bristlenose Plecostomus
Green Spot (Coleochaete) Small, hard green spots on glass, equipment, live plants and decor Nutrient imbalance or low phosphorus levels

Low CO2

Too much light

Check/adjust phosphate levels

Increase CO2

Reduce light

Nerite snails
Green Water (Euglena) Free-floating microscopic algae bloom fills your tank with densely green water New Tank Syndrome

A sudden increase in light (sunlight)

Nutrient spike from overfeeding or poor maintenance

Wait for tank to finish cycling

Lower or eliminate aquarium light

Correct nutrient balance

Add UV Sterilizer to tank

Snails

Shrimp

Blue Green (Cyanobacteria) Slimy mat of blue, green, brown or reddish-purple algae spreading across substrate and front of the aquarium Poor water quality

Poor filtration and circulation

Infrequent water changes

Too much light

Increase water change frequency and amounts

Improve filtration and circulation

Reduce or eliminate light in the tank (blackout)

Use antibiotics to kill bacterial infection

None known

Tips For Algae Control

detail of man's hand coming out of the aquarium during his cleaning. Household chores concept

You may have noticed some themes as I described the causes of and solutions to algae outbreaks in our home aquariums. While an algae bloom may be something you have to wait out as your new tank cycles, in mature tanks they are usually a sign of a bigger problem. To prevent algae blooms in your freshwater tank:

  • Add a variety of algae eaters to your community to naturally clean the aquarium.
  • Keep up with your water changes and routine maintenance.
  • Don’t overstock your tank with too many fish, snails and invertebrates.
  • Don’t overfeed your fish or leave excess food in their tank to rot.
  • Use the right number of 3-stage filters for your tank size and replace the filter pads and media on a regular schedule.
  • Limit the amount of natural sunlight that hits your tank and keep your aquarium lights on a timer. Most tanks do not need more than 9 hours a day of light, so cut your schedule back if you’re having algae problems.
  • UV Sterilizers can kill free-floating algae cells and prevent some outbreaks.

21 Best Freshwater Algae Eaters

Catfish ancystrus at the bottom of the aquarium

Let’s take a look at some of the best and most popular algae eating fish, snails and shrimp for freshwater aquariums. One thing to keep in mind is that most algae eaters are very sensitive to their water quality. If you have detectable levels of ammonia in your tank they will suffer. You’ll need to keep your tank clean to keep them working!

Invertebrate algae eaters are often very sensitive to plant fertilizers and aquatic medications that contain copper. Be sure the products you use in your tank are safe for your new pets!

1. Siamese Algae Eater

Finchville Aquatics Siamese Algae Eater (Crossocheilus Siamensis)

BUY ONE HERE

 

An excellent option for tanks over 20-gallons, the Siamese Algae eater or SAE is an eating machine. Even though these omnivorous fish prefer live foods they are some of the few that will consume hair and black beard algae! Not to be confused with the nearly identical Flying Fox fish, the SAE is a great option for algae control.

These social and energetic fish enjoy hanging out together and feeding on algae and food scraps. They are not aggressive but their activity can be distressing to bottom feeders and other territorial fish, so they are not a good option for cichlid tanks. They can also get nippy around long fins, so avoid keeping with Angelfish and Discus.

Common Name (species) Siamese Algae Eater, SAE (Crossocheilus siamensis)
Family Cyprinidae
Temperament Peaceful, active and social
Care Level Easy
Diet Omnivorous; prefers live foods but will eat algae. One of the few fish to consume BBA!
Color Grey/gold body with a black stripe running from mouth to the tip of the tail fin
Size 5 to 6 inches in length
Minimum Tank Size 20 gallons
Temperature Range 75 to 79°F
Water Hardness 5 to 20 KH
pH Range 6.5 to 8
Compatibility with Tank Mates Active fish is best kept with other peaceful community fish. May nip at fish with long fins. Not ideal for cichlid tanks and may disturb territorial bottom feeders due to their activity

2. Chinese Algae Eater

A golden Gyrinocheilus aymonieri.
Image Source: commons.wikimedia.org

The oddly-named Chinese Algae eater is not native to China, but it does have a voracious appetite and a preference for eating algae. Unfortunately, this Southeast Asian species also outgrows its love of algae and turns into a bit of an obnoxious problem child as it matures. These semi-aggressive are not ideal for peaceful tanks.

If you have a large semi-aggressive community tank over 50-gallons you may be able to slip a Chinese algae eater inside without any problems. The young fish feast continually on algae and they’ll still snack on it as they grow. Since they do establish and defend their territory you should only keep one fish per aquarium.

Common Name (species) Chinese Algae Eater, Indian Algae Eater, Sucking Loach
(Gyrinocheilus aymonieri)
Family Gyrinocheilidae
Temperament Semi-aggressive and territorial
Care Level Moderate to Hard
Diet Omnivorous; algae when young, insects and larvae, worms
Color Pale brown with black stripe or spots on the body; albino and golden varieties available
Size 10 to 11 inches in length
Minimum Tank Size 50 gallons
Temperature Range 71 to 80°F
Water Hardness 8 to 10 KH
pH Range 6.0 to 8.0
Compatibility with Tank Mates Best kept solo or with smaller fast-swimming fish such as Tiger Barbs that avoid the bottom and middle of the tank. Not ideal for peaceful community tanks. Avoid housing with Discus, invertebrates or other Chinese or Siamese algae eaters

3. Twig Catfish

If you have a large, densely planted mature tank over 40-gallons you might consider adding one of the most unique looking algae eaters on the list—the Twig Catfish. These funny-looking fish resemble a branch or stick and are the masters of disguise. They love to attach themselves to plants or bogwood in your tank as they feed.

These shy algae eaters are ideal for peaceful community tanks and are happy to be with their own kind and other friendly species. They are extremely sensitive to changes in their water quality which makes them a bit tricky to maintain. But they add an interesting element to your tank and do a great job keeping algae under control.

Common Name (species) Twig Catfish (mostly Farlowella vittata or acus)
Family Loricariidae
Temperament Peaceful and shy
Care Level Moderate to Difficult
Diet Omnivorous but mostly vegetarian; eats biofilm, algae and blanched vegetables. Occasional treats of brine shrimp, bloodworms or Daphnia eggs readily accepted
Color Light brown with darker brown lines or spots
Size Grows up to 6-inches in length
Minimum Tank Size 40 gallons
Temperature Range 75 to 79°F
Water Hardness Soft to hard as long as it’s consistent
pH Range 6.0 to 7.0
Compatibility with Tank Mates Best kept with other twig catfish or in community tanks with small, friendly fish such as Cory Cats, Neon or Rummy Nose Tetras or Pearl Danios

4. Otocinclus Catfish

Dwarf suckermouth catfish. You might think he looks like a tasty mouthful, but look closer and you'll see he's completely covered in spines.
Image Source: flickr.com

If you’re looking for small algae eaters or options for controlling brown algae outbreaks consider the Otocinclus Catfish, commonly known as the Otto. Ottos only grow to a maximum of 2-inches long so they’re a suitable option for most tanks. These peaceful fish enjoy schooling and shoaling together in between meals.

Like many catfish, the Otto is a scavenger but unlike most they are also an herbivore and feed entirely on algae and decaying plant materials. A group of these algae-eating monsters can prevent outbreaks or blooms, and they work with most peaceful community groups. They are one of the best options for algae control!

Common Name (species) Otocinclus, Ottos, Dwarf Sucking Catfish, Midget Sucking Catfish (Otocinclus vestitus)
Family Loricariidae
Temperament Peaceful schooling fish
Care Level Easy
Diet Herbivore; algae and decaying plant materials
Color Grey body speckled with black spots
Size 1 to 2 inches in length
Minimum Tank Size 10 gallons
Temperature Range 72 to 82°F
Water Hardness 6 to 15 KH
pH Range 6 to 7.5
Compatibility with Tank Mates Best kept in a school along with other small peaceful community fish such as tetras, rasboras and loaches

5. Whiptail Catfish

Whiptail Catfish, sturisomas sp., Adult

If you thought the Twig Catfish looked interesting but too hard to maintain then check out the similar-looking Whiptail Catfish! The Whiptail Cats are closely related to the Twigs but are smaller and much easier to care for. Unfortunately, the Whiptail is also an omnivore and prefers to eat things other than your aquarium algae.

Whiptail Cats will snack on the algae in your tank but they prefer to eat algae wafers and food scraps. You may need to encourage them to pick the algae if you’re having a problem, but in between blooms you should supplement their diet with catfish pellets and sinking wafers. These fish are actually a lot of fun to observe, too!

Common Name (species) Whiptail Catfish (multiple Rineloricaria species)
Family Loricariidae
Temperament Peaceful
Care Level Easy
Diet Omnivorous; prefers a carnivorous diet of catfish pellets and algae wafers to eating tank algae
Color Pale to dark brown with darker colored stripes or speckles
Size Varies by species but usually 3 to 6 inches in length
Minimum Tank Size 20 gallons
Temperature Range 72 to 79°F
Water Hardness 3 to 15 KH
pH Range 6.0 to 7.5
Compatibility with Tank Mates Best kept with a few other whiptails or in a peaceful community tank without aggressive or nippy species

6. Bristlenose Plecostomus

Ancistrus, bushynose catfish, Loricariidae freshwater fish on driftwood, frontal head macro headshot

One of the best options for eating algae in a tank over 25-gallons is the fascinating Bristlenose Plecostomus. More popular than the larger and semi-aggressive Common Pleco, the Bristlenose develops long tentacles around its snout upon reaching maturity. This gives them their unique brushy-nosed appearance.

The Bristlenose is mostly vegetarian and does a number on the algae in your tank. They are especially good at eradicating Green Dust and Brown algae blooms, but they’ll snack on most types. They also like to chew on driftwood, especially as they get older. This is one of my favorite algae eaters for community tanks!

Common Name (species) Bristlenose Plecostomus, Bushy Nose Catfish, Brushmouth Pleco (multiple Ancistrus species)
Family Loricariidae
Temperament Peaceful and mellow
Care Level Easy
Diet Primarily Herbivorous; algae, wood and vegetables and food scraps
Color Varies; may be brown, black, olive, grey, golden/orange or albino with light white or yellow spots
Size Up to 5 inches in length
Minimum Tank Size 25 gallons
Temperature Range 60 to 80°F
Water Hardness 6 to 10 KH
pH Range 6.5 to 7.5
Compatibility with Tank Mates Best kept with other peaceful community fish like tetras, minnows, gouramis and rasboras, although larger specimen may work in a semi-aggressive barb tank as well

7. Garra AKA Doctor Fish

Garra rufa
Image Source: commons.wikimedia.org

The Garra is an interesting fish. You may have seen this species in a beauty salon that advertises “fish pedicures.” These 4 to 5-inch fish feed mostly on biofilm and are known for their ability to nibble the dead skin off our feet and hands. They don’t actually ingest the dead skin and I can’t recommend using them for this purpose.

But Garra or Doctor Fish, as they’re also known, are great algae consumers and a good option for mature planted community tanks. They are easy to keep in small groups as long as you have the room but can get nippy when stressed. They are able to climb too, so be sure your hood is secure if you choose them for your tank.

Don’t confuse the Garra rufa with the similarly-named Panda Garra, which does not eat algae and is semi-aggressive. But if you want a fish that cleans tanks, consider adding a group of these loach-like creatures to your mature tank and algae won’t be a problem for long.

Common Name (species) Garra, Doctor Fish, Pedicure Fish (Garra rufa)
Family Cyprinidae
Temperament Peaceful but will scrap with other fish if their tank is too small
Care Level Easy to Moderate
Diet Omnivore; prefers biofilm over algae
Color Grey
Size 4 to 5 inches in length
Minimum Tank Size 30 gallons
Temperature Range 68 to 89°F
Water Hardness 6 to 10 KH
pH Range 6.8 to 7.2
Compatibility with Tank Mates Best kept in small groups in mature community tanks with peaceful occupants

8. Fancy Mollies

Molly fish isolated on a black background

I’m a huge fan of livebearers, and Fancy Mollies are both a colorful and practical option for algae eaters in a community tank. There are more than 20 species of molly fish including popular short finned varieties and fancier types like the Sailfin Molly. They come in a rainbow of bright colors and have many unique patterns too.

Mollies are closely related to the fancy and wild-type guppies. These omnivores love to feast on algae, and they also eat fish flakes and live food like brine shrimp. They are very easy to maintain and are a great option for novice fish keepers. If you’d like to breed fish this is an excellent species to start with!

Experienced aquarists shouldn’t overlook these guys either, because they are a lot of fun and add splashes of color to planted tanks. They also spend their time in the middle and top of the tank. I think everyone should give a Molly tank a try at least once, and they’re definitely the most vivid and colorful algae eater on my list!

Common Name (species) Fancy Mollies, Molly Fish (multiple species of Poecilia)
Family Poeciliidae
Temperament Peaceful and social
Care Level Easy
Diet Omnivore; algae and plant materials, small invertebrates like brine shrimp
Color Colors and patterns vary widely but include red, orange, yellow, black and white varieties
Size Up to 4.5 inches in length
Minimum Tank Size 10 gallons
Temperature Range Tropical 72 to 79°F
Water Hardness Hard or soft water as long as it’s stable
pH Range 7.0 to 8.5
Compatibility with Tank Mates Best kept in groups but does well with other peaceful tropical community fish. Mollies may nip at each other if they don’t have enough space

9. Sailfin Plecostomus

Sailfin pleco (Pterygoplichthys gibbiceps) in a fish tank
Image Source: commons.wikimedia.org

If you need an algae eater for a big tank 100-gallons or larger than you can’t go wrong with the Sailfin Plecostomus. These showy catfish can grow up to 20-inches in length and have a prominent and upstanding dorsal fin which looks a bit like the sail on a boat. They have huge appetites and can really plow through the tank algae!

Sailfins are one of the species that will eat brown algae, but they will also snack on other types. As they mature you may find them hanging out on your drift or bog woods too. They are a peaceful fish, but can be territorial and they often like to snack on the slime coat of other fish.

It’s best to keep them with small, fast-swimming species so they can’t sneak in for a snack-attack. While they won’t intentionally kill other fish, they are scavengers and will eat leftover food scraps and the remains of any deceased community fish.

Common Name (species) Sailfin Plecostomus, Clown Pleco, Leopard Pleco (Pterygoplichthys gibbiceps)
Family Loricariidae
Temperament Peaceful community fish, but can be territorial and may snack on the slime coat of large slow swimmers like Angelfish or Discus
Care Level Easy
Diet Omnivore but primarily vegetarian; eats algae, wood and other plant materials along with food scraps
Color Base color varies from orange to brown with darker brown spots covering the body and fins
Size Up to 20 inches in length
Minimum Tank Size 100 gallons
Temperature Range Tropical 73 to 85°F
Water Hardness 6 to 10 KH
pH Range 6.5 to 7.5
Compatibility with Tank Mates Best kept as the only pleco in the tank and housed with other peaceful community fish like tetras, gouramis and loaches

10. Rubber Lipped Plecostomus

Another option is the Rubber Lipped Plecostomus, not to be confused with the Rubber Pleco, which is larger. The Rubber Lipped looks like a small, typical pleco and is often confused for a juvenile of another species. You may have one and not even know it.

These guys grow up to 7-inches long, and like the Bristlenose they are mostly vegetarian and eat brown algae specifically. They’ll also snack on the green algae and any wood in your tank. Like most catfish they are scavengers and will help keep food scraps to a minimum.

Common Name (species) Rubber Lipped Plecostomus, Striped Pleco
(Chaetostoma milesi)
Family Loricariidae
Temperament Peaceful and mellow community fish
Care Level Easy
Diet Omnivore but mostly vegetarian; eats algae, wood and other plant materials along with food scraps
Color Grey to brown with darker patterns of stripes on the body and head
Size Up to 7 inches in length
Minimum Tank Size 25 gallons
Temperature Range 72 to 80°F
Water Hardness 8 to 12 KH
pH Range 6.5 to 8
Compatibility with Tank Mates Does well with other peaceful community fish but avoid housing with semi-aggressive or aggressive species

11. American Flagfish

Florida Flagfish (Jordanella Floridae)
Image Source: flickr.com

If you want an interesting group of algae eaters to build an aquarium around then you can’t do it better than with the American Flagfish. Named for the colors and scale pattern on the males, American Flagfish are vivid and very fun to watch. Unfortunately, they are also semi-aggressive and best kept on their own.

Flagfish are voracious eaters and particularly enjoy eating hair and black beard algae. They also snack on insects, crustaceans and their eggs when they can find them. Adding these fish makes for an active and attractive planted tank. They won’t eat your plants but they sure will keep your tank clear of algae!

Flag fish are fairly easy to maintain and very hearty. The only problem is they don’t tend to do well in community tanks due to their aggression and territoriality. I’d keep a group of these guys in their own tank. Another thing I’ve noticed is these fish don’t usually photograph very well. Their iridescent scales are best appreciated in person.

Common Name (species) American Flagfish, Florida Flagfish, American Killifish (Jordanella floridae)
Family Cyprinidae
Temperament Semi-Aggressive; male fish are territorial and both genders will nip at other fish
Care Level Moderate
Diet Omnivore; algae (especially hair algae), crustaceans, insects and eggs and plant materials
Color Iridescent scale pattern. Female fish are olive with turquoise highlights and male fish have red and blue highlights that resemble the American flag
Size Up to 2.5 inches in length
Minimum Tank Size 20 gallons
Temperature Range 66 to 86°F
Water Hardness 6 to 20 KH; prefer hard to very hard water
pH Range 6.5 to 8.5
Compatibility with Tank Mates Best kept in groups of 5 or more. Not ideal for community tanks but may be housed with smaller, fast swimming fish like minnows or rasboras if the tank is large enough

12. Nerite Snail

Imperial Tropicals 2 Tiger Nerite Snails (Neritina natalensis) - Great for Algae and Plant Safe - Will not reproduce in Fresh Water!

BUY ONE HERE

 

If you’d like one of the top algae eaters in the world then look to the various types of Nerite Snails. There are more than 200 species of these small mollusks in the world and many are suitable for freshwater aquariums. They’re even available in fancier patterns and colors like the Tiger, Zebra and Horned Nerite!

Nerite snails are calm and peaceful invertebrates who primarily feed on biofilm and are the only species of algae eater that can tackle green spot algae! They don’t grow bigger than an inch in diameter and are suitable for mature non-aggressive community tanks of all sizes. They often hang out above the water line.

They do prefer soft soil or sand substrates to harsh aquarium gravel, which could injure their antennae or foot. They also need plenty of rocks and wood for hiding places. Like all the aquatic snails, Nerites are very sensitive to ammonia and copper and need fairly hard water with plenty of calcium to prevent shell thinning.

Common Name (species) Nerite Snail, Zebra Nerite, Tiger Nerite, Horned Nerite
(multiple genus and species)
Family Neritidae
Temperament Peaceful and active
Care Level Easy
Diet Herbivore; biofilm, algae and decomposing plant materials
Color Varies by species
Size Up to 1 inch in length and diameter
Minimum Tank Size 5 gallons
Temperature Range 72 to 78°F
Water Hardness 5 to 15 KH; prefer hard water and high calcium to prevent shell thinning
pH Range 7.0 to 8.2
Compatibility with Tank Mates Great option for community tanks as long as they don’t contain any species that eat snails

13. Rabbit Snail

a chocolate rabbit snail
Image Source: Here

If you’re looking for a really interesting algae eater for tanks 30-gallons or bigger consider the long-faced Rabbit Snail. These big mollusks can get up 5-inches in diameter and length and have long, wrinkled proboscis and antennae that make them resemble a stuffed rabbit or elephant.

Rabbit snails come in a variety of shell colors but their body is usually a bright yellow or orange, which really pops in your planted aquarium. Their spiral-shaped shell looks like an ice cream cone and they really do have a comic appearance as they move around the tank to feed.

They are super algae eaters and will also take care of any decaying plants or leftover food scraps. They don’t usually eat plants but may snack on your Java Fern. Rabbit snails need conditions similar to the other snails and prefer sand over gravel substrates. Avoid housing with aggressive species or snail-eaters like crayfish.

Common Name (species) Rabbit Snails, Poso Snails, Elephant Snails
(multiple Tylomelania species)
Family Pachychilidae
Temperament Peaceful and active
Care Level Easy
Diet Omnivore; algae, decaying plant material, Java Fern and food scraps
Color Shell colors vary but body, proboscis and antenna are a bright yellow to orange and prominently wrinkled
Size 3 to 5 inches in length and diameter
Minimum Tank Size 30 gallons
Temperature Range 68 to 84°F
Water Hardness 2 to 15 KH; prefers hard water and high calcium to prevent shell thinning
pH Range 6.5 to 7.5
Compatibility with Tank Mates Best kept with peaceful community fish with similar care requirements like dwarf loaches, shrimp and tetras.

14. Ramshorn Snail

Snail red ramshorn inside tank.

The next snail I’m going to talk about is one that can be considered a bit of an aquarium pest at times. The Ramshorn Snail is an impressive algae eater but the truth is most of us end up with them in our tanks by accident. These guys are notorious hitchhikers and often seem to appear out of nowhere!

They are explosive breeders as well, so if you have them in your aquarium you can expect to see babies. If you don’t have community members who can consume the eggs or young ones you may need an Assassin snail to keep the population from getting out of control.

Ramshorn snails are small and come in a variety of colors, and these guys love to eat! You’ll see them cleaning the algae from your glass and decor, and they enjoy hanging out on brown leaves and munching on the decaying vegetation. They do an excellent job of keeping a tank clean and free of food scraps as well.

Common Name (species) Ramshorn Snail (Planorbella duryi and corneus)
Family Planorbidae
Temperament Peaceful and active
Care Level Easy
Diet Omnivore; algae, decaying plant material, food scraps
Color Shells vary from light to dark brown but can also be blue, red or spotted. The body is either black or red
Size Up to 1 inch in diameter
Minimum Tank Size 5 gallons
Temperature Range 70 to 78°F
Water Hardness 5 to 15 KH; prefers hard water and high calcium to prevent shell thinning
pH Range 7 to 8
Compatibility with Tank Mates Best kept with peaceful community fish with similar care requirements like Cory Cats, gouramis and shrimp. May need to use Assassin snails for population control

15. Malaysian Trumpet Snail

Malaysian Trumpet snail
Learn more at : flickr.com

Another snail that has a reputation for their free-breeding ways, the Malaysian Trumpet Snail or MTS has a spiral shell similar to the Rabbit snail. But these small invertebrates are nocturnal and burrow into your substrate during the day. You’ll see the tip of their shell peek out from below the sand while the lights are on.

At night, the MTS scours your tank for algae and rotting vegetation and cleans up any leftover food scraps. They don’t usually feed on live plants unless they are not finding enough food. Since they are livebearers, they don’t lay eggs like other snails and actually give birth to the tiny babies.

Trumpet snails can quickly take over your tank if conditions are right, so you may need to bring in an Assassin snail if things get out of hand. Because they like to bury themselves in your substrate they are best kept in a sand or soil tank to prevent injury. But these guys are easy to keep and really clear the algae away!

Common Name (species) Malaysian Trumpet Snail, MTS (Melanoides tuberculata)
Family Thiaridae
Temperament Peaceful and active (at night)
Care Level Easy
Diet Omnivore; algae and decaying plant material, food scraps
Color Light brown shell with darker markings and a grey body (foot)
Size Up to 1 inch in length and diameter
Minimum Tank Size 5 gallons
Temperature Range 70 to 80°F
Water Hardness 5 to 15 KH; prefers hard water and high calcium to prevent shell thinning
pH Range 7 to 8
Compatibility with Tank Mates Best kept with peaceful community fish with similar care requirements like tetras, gouramis and shrimp

16. Mystery Apple Snail

White Mystery Snail - 1/2-2 inches - Algae Eater for Aquariums

Get One Here

 

Don’t confuse the Mystery or Common Apple Snail with the larger invasive Apple snail. Mystery snails are native to the Americas and not Asia like their invasive cousins. These snails look a lot like a fancy version of a garden snail, with a round spiral shell that grows to about 2-inches in diameter.

Some Mystery snails have a plain brown shell but many come in vivid hues like gold and purple. Their bodies have iridescent markings too, with long drooping tentacles. These calm herbivorous creatures spend their time eating algae from your tank and cleaning up decaying plant materials.

These snails are easy to keep and especially suited to aquatic communities since they prefer well oxygenated water. They enjoy roaming around a densely planted tank and get along with other peaceful community fish and shrimp. They are also the only snail species on my list that can eat the fast-growing hair algae!

Common Name (species) Mystery Apple Snail, Mystery Snail, Common Apple Snail (Pomacea bridgesii)
Family Ampullariidae
Temperament Peaceful and calm
Care Level Easy
Diet Herbivore; algae, decaying plant material. Only snails that feed on hair algae!
Color Shells may be brown, black, blue, purple, gold or white while body color varies from grey to yellow
Size Up to 2 inches in diameter
Minimum Tank Size 5 gallons
Temperature Range 68 to 84°F
Water Hardness 12 to 18 KH; prefers hard water and high calcium to prevent shell thinning
pH Range 7.6 to 8.4
Compatibility with Tank Mates Best kept with peaceful community fish with similar care requirements like gouramis, tetras, rasboras and shrimp

17. Amano Shrimp

Amano Shrimp (Caridina japonica)

BUY ONE HERE

 

It won’t take you long to understand why this Japanese algae eater is so beloved! Next to the Cherry Shrimp covered below, the Amano Shrimp is the most popular crustacean in the aquarium trade and a top choice as an algae eater. They readily consume hair and black beard algae and help keep green water algae under control.

These peaceful but rather plain shrimp don’t stand out in your mature tank and usually blend in with your plants, rocks and decorations. They are biofilm and algae-busters extraordinaire and have massive appetites. You’ll definitely see them scrambling for food scraps at meal time!

This species has recently undergone a name change, which could lead to some confusion. The current scientific name is Caridina multidentata but some stores still sell them under the old name, Caridina Japonica. No matter what you call them, this is a great option for controlling algae in a mature planted shrimp and snail tank.

Common Name (species) Amano Shrimp, Yamato Shrimp, Caridina Japonica
(Caridina multidentata)
Family Atyidae
Temperament Peaceful; very active at feeding time
Care Level Easy
Diet Omnivore; biofilm, algae, plant materials, leftover food scraps
Color Translucent silver-blue body with grey/blue or brown/red dots
Size Up to 2 inches in length
Minimum Tank Size 10 gallons
Temperature Range 60 to 80°F
Water Hardness 0 to 8 KH
pH Range 6.0 to 7.6
Compatibility with Tank Mates Best kept in mature tanks with other peaceful community fish that are small enough they can’t eat the shrimp. Good options are other dwarf shrimp, freshwater snails, danios, guppies, mollies, platys and tetras

18. Cardinal  Sulawesi Shrimp

Sulawesi Shrimp (Caridina dennerli)

One of the most stunning algae eaters is a relative newcomer to the aquarium trade, the Cardinal Sulawesi Shrimp. Their vivid bright red speckled carapace and white front legs look amazing in a planted tank! They are an ideal pick for a mature tank that is plant or shrimp focused rather than fish-focused.

The Cardinal has a couple of downsides and isn’t the best choice for beginning aquarists. They’re picky eaters and are frequently out-competed by more active shrimp and fish. They prefer to feed on biofilm and algae and often won’t eat sinking food or algae disks. You may need to supplement their diet with powdered spirulina.

This species is also listed on the IUNC red list as critically endangered. If you opt for creating a tank for Cardinal shrimp be sure your pets have been captive bred and not captured from the wild. They may not be ideal for active community tanks, but the Cardinal makes a great algae eater for a themed or specialty shrimp tank!

Common Name (species) Cardinal Sulawesi Shrimp, Cardinal Shrimp (Caridina dennerli)
Family Atyidae
Temperament Peaceful and shy
Care Level Moderate to Hard
Diet Omnivore; biofilm, algae, decaying plant materials, food scraps
Color Red body (shade varies) with white speckles; front legs are white
Size Approximately ½ to 1 inch
Minimum Tank Size 10 gallons but bigger is better
Temperature Range 77 to 86°F
Water Hardness 3 to 10 KH
pH Range 7.8 to 8.2
Compatibility with Tank Mates Prefers to be kept in groups of 15 or more in a mature tank; best kept with other small, peaceful community species that won’t eat them

19. Cherry Shrimp

Cherry Shrimp, 0.5"-1" (Neocaridina sp.)

BUY ONE HERE

 

The most popular freshwater invertebrate on the market is this coldwater algae eater, the Cherry Shrimp. Cherries make a great option for mature planted community tanks 10-gallons or bigger and are easy to maintain. These bright red shrimp average about 1.5-inches in length and eat everything from biofilm and algae to rotting plants and food scraps.

Cherry shrimp are active in the daytime, and you’ll find this crustacean keeps busy cleaning your plants and searching your substrate for food. They need to have some moss in their tanks because they groom themselves with it. Consider keeping Java Moss or a similar, easy-to-grow variety around for your Cherries.

As long as you have a shrimp-friendly population inside your tank you should have no problems keeping these active eaters. Unlike most invertebrates, Cherries do fine in graveled tanks and don’t mind living in cool or warm waters. That makes them a viable option for goldfish tanks and tropical community aquariums!

Common Name (species) Cherry Shrimp, Red Cherry Shrimp (Neocaridina davidi)
Family Atyidae
Temperament Peaceful and Active
Care Level Easy
Diet Omnivore; biofilm, algae, decaying plant materials and food scraps
Color Red
Size 1.5 inches
Minimum Tank Size 10 gallons
Temperature Range 65 to 85°F
Water Hardness 3 to 15 KH
pH Range 6.5 to 8
Compatibility with Tank Mates Best kept in small groups in mature tanks with other peaceful community fish like goldfish, gouramis, small tetras, snails and other dwarf shrimp

20. Bamboo Shrimp

Close-up view of Freshwater Bamboo Shrimp. Atyopsis moluccensis.

If you’d prefer a unique algae eater that you don’t commonly see in aquariums then take a look at the Bamboo Shrimp. These filter-feeding shrimp are not bottom-dwellers. Instead, they have broad fan-shaped arms they use to catch microscopic particles of food with.

Bamboo shrimp hang out on plants or rocks in a current and wave their fans around to capture floating algae and food scraps from the water. These fans contribute to their flamboyant appearance and helped earn them the nickname “Singapore Flower Shrimp.” They’re also the reason these shrimp are fairly difficult to maintain.

It’s not their care but their feeding that presents problems. It can be hard to supply enough food for a filter feeder in a community aquarium. You may need to supplement your shrimp with powdered foods and spirulina and place it upstream so it flows towards their fans. They are a very original and pretty algae eater!

Common Name (species) Bamboo Shrimp, Singapore Flower Shrimp, Wood Shrimp (Atyopsis moluccensis)
Family Atyopsis
Temperament Peaceful
Care Level Moderate to Difficult
Diet Omnivore; filter feeder requires fine food particles like powdered algae, baby shrimp diets and ground fish flakes
Color Red-brown, green or yellowish shell with white stripes
Size 1 to 3 inches in length
Minimum Tank Size 20 gallons but bigger is better
Temperature Range 75 to 82°F
Water Hardness 2 to 6 KH
pH Range 6.5 to 8
Compatibility with Tank Mates Best kept in mature tanks with other small, peaceful community fish such as tetras, minnows, snails and other dwarf shrimp. Due to feeding habits it may be hard to maintain multiple bamboo shrimp in the same habitat

21. Ghost Shrimp

KOOL TOOLS 21 Freshwater Ghost Shrimp (Glass Shrimp, Ghost Shrimp)

BUY ONE HERE

 

Our last algae eater is another of my favorites, the Ghost Shrimp. These dwarf shrimp have a translucent carapace you can see straight through. You can even see their stomach and internal organs! If you’re looking for an algae eater for a coldwater goldfish tank or as a tank mate for a Betta fish you probably can’t make a better pick!

Also known as Glass shrimp, these funny crustaceans are peaceful but need plenty of room. They tend to squabble if pressed for space. But they are not aggressive and make a great addition to a mature planted aquarium. They prefer sand or fine gravel to coarser stuff but otherwise are really easy to maintain.

Common Name (species) Ghost Shrimp, Glass Shrimp (multiple Palaemonetes species)
Family Palaemonidae
Temperament Peaceful, but may fight if they don’t have enough space
Care Level Easy
Diet Omnivore; biofilm, algae, decaying plant materials, food scraps
Color Translucent shell; internal organs are visible
Size 1.5 to 2 inches in length
Minimum Tank Size 10 gallons
Temperature Range 65 to 85°F; 75°F is ideal
Water Hardness 3 to 10 KH
pH Range 7.8 to 8
Compatibility with Tank Mates Best kept solo or in small groups in mature tanks, or with other peaceful community species. They don’t care to be crowded

Conclusion

close up image of landscape nature style aquarium tank with a variety of aquatic plants inside.

As you can see, you have a lot of options when it comes to picking the best algae eating fish or invertebrate for your tank. Buying a couple of types of algae eaters for your aquarium is an easy and natural way to keep the algae under control and the food scraps to a minimum. They add a nice bit of flare to your tank as well.

There are other methods for clearing problem algae from your tank, like adjusting your lights and altering the water chemistry. Keeping some of these species in your tank may prevent algae blooms from occurring, so you don’t have to resort to more labor-intensive efforts. I hope you’ve enjoyed this detailed guide to freshwater algae eaters, and we’d love to hear more about your pick in the comments!

Check out our infographic and don’t forget to share!

Complete Guide to the Best Algae Eaters - infographics

Jen has more than 30 years experience as a biologist, aquarist, and fishkeeper. She is an expert in setting up new tanks and maintaining naturally-planted freshwater habitats, and has experience raising a wide variety of aquatic species.

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