20 Best Freshwater Algae Eaters

It is not easy to remove algae after they rapidly start populating your fish tank. However, by cultivating algae eaters, you can effortlessly eliminate algae from your tank and keep it clean, safe, and healthy for your fish and other critters. 

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In this article, I will share with you a list of the twenty best algae eaters and what you need to know about them. 

The best algae eaters for home aquariums

  1. Otocinclus Catfish

The Otocinclus Catfish aka the Oto catfish is one of the most commonly used algae eaters in the Western World. It is commonly used because it is a very effective algae eater. It is also commonly used because it is a low-maintenance fish.

If you watch videos of award-winning aquarium set ups built by experienced aquarists, you will almost always see an Oto catfish. This is because experienced aquarists know from experience how effective the catfish species is at cleaning algae from fish tanks. 

Larger catfish species are also good algae eaters. However, they are not great for keeping in home aquariums because they knock slow-moving fish, they are territorial, they eat live plants, and they knock over potted plants. In contrast to its larger cousins, the Oto catfish is very docile and does not disturb other fish or organisms in aquariums.

Otocinclus catfish grow to a maximum length of about 1 inch. Because of their tiny size, they are considered the best algae eaters to keep in nano aquariums. Moreover, their tiny size enables them to reach and clean spots that bigger algae eaters cannot reach. 

If you decide to get this species of fish for your tank, you should get three or five of them because they are a schooling fish and are, therefore, happy together. Moreover, you should add live plants to your aquarium and caves to providing hiding spaces for them in case you are keeping a semi-aggressive or aggressive fish that might decide to disturb them or have them for lunch. 

In addition to being effective algae removers, the Oto catfish are entertaining to have in an aquarium. This is because they do harmlessly squabble with each other from time to time. Generally, you can use an Oto catfish (ideally several of them) to clean any aquarium. 

  1. Bristlenose Plecos

The Bristlenose Plecos aka plecos are a great fish species to have in your tank regardless of whether you have an algae infestation. This is because they are true catfish and are pleasing to look at. Male plecos are bigger than female ones and have got bigger whiskers. This makes them easy to identify. It also makes them add character to any tank they are introduced into.

The best thing about plecos is that they are a hardy fish. This means they can pretty much handle a wide range of different water parameters. And the best thing about them as algae eaters is that they have got a huge appetite. This means that they will not spare any algae they come across and will pretty much keep your tank algae free. (NB Since plecos have got a huge appetite, you should feed them with bits of algae wafers to supplement the algae food they scavenge from your tank). 

Unlike the Oto catfish that have a maximum length of 1-inch, plecos grow to a length of about 5 inches. This means they are better suited for bigger aquariums (20 gallons and higher). And despite their big size, Bristlenose Plecos are not territorial. They do not disturb other fish or critters in the tank. 

If you decide to introduce one or two plecos in your tank, you should make sure you add natural driftwood. The wood will help your plecos with their digestion. It will also improve their health and wellbeing. 

  1. Black Mollies

Many aquarists do not use black mollies as algae eaters even while they do know that they are very decent algae eaters. I do not know the reason why and I will not speculate. What I do know is that mollies clear algae-like nobody’s business. I also know that they particularly love to remove hair algae. 

If you do not really like plecos and Oto catfish, you should strongly consider black mollies. They are a very effective and attractive algae eater. They are also relatively active compared to other algae eaters. 

The one thing that is very interesting about black mollies is that they reproduce really fast. Within a couple of months, two mollies can bear several dozen mollies. So if you have a big tank, you do not really need to buy many at once. It will be a waste of money. You will simply need to buy two opposite sex black mollies and they will multiply in double quick time to increase their algae-removal power multiple times.  

Because black mollies are omnivores, they are not as powerful as other algae eaters on this list of 20. However, they are usually just as good and clean the upper and middle parts of the tank very well. You can include them in your tank to eat algae in the top half of your tank and get other algae eater e.g. a Bristlenose Pleco to eat algae in the bottom half of your tank. 

You can use a black molly to clean algae in both freshwater and saltwater tanks. 

  1. Doctor Fish

Doctor Fish

You can use doctor fish aka Garra to get rid of algae in your fish tank. Over the last couple of years, people have been using Garra fish in spas to clean off dead skin from hands and feet. This is because the fish species is known to feast on free organic matter. While doctor fish eat any loose organic matter, they are known to prefer a diet of algae and detritus. Therefore, having them in your tank will eliminate both algae and detritus from it.

In my opinion, the best thing about using doctor fish as algae cleaners in your tank is that they are a hardy fish. This means they can survive in most aquarium environments.  So if you have a unique aquarium environment with unusual water parameters, you are better off using them as your algae cleaners. 

While Garra are decent algae and detritus eaters, if you decide to keep them, you are going to need to supplement their diet with healthy food such as algae wafers, algae flakes, and bloodworms. Doing this will keep them happy and healthy. 

If you decide to use this fish species as your algae cleaner, you should buy four or five of them as they love staying in groups. 

  1. Siamese Algae Eater

As the name of this fish suggests, it is best known for eating algae. According to experienced aquarists, this fish is unparalleled in terms of its effectiveness in eating algae. Many aquarists use it to clean algae because it has a very good appetite for the aquatic plants. 

The word Siamese in the name of this fish might make you associate it with Siamese fighting fish aka betta fish. And this might make you think that Siamese algae eaters are very territorial and aggressive. However, this is not the case. Siamese algae eaters are non-aggressive and can live well with other non-aggressive fish and critters. 

You can buy Siamese algae eaters to feed on any algae type in your tank. However, they are best known for their work on black algae. This is because they prefer black algae as food. A small group of around five of this fish species can clean a large tank within just a couple of days. This is because the fish are fast-moving and very active. 

Perhaps the best thing about them is that they can also eat algae from aquarium plants without hurting the plants. Not many algae-eating fish and critters can do this.  

  1. Twig Catfish

A twig catfish is a specialized pleco fish. It is a fish that may appear weak in appearance but it has a massive appetite for all things algae. In nature, a twig catfish can grow to a maximum length of about six inches and it will usually hide among plants, under rocks or driftwood. So it is a generally shy fish. What this means is that if you decide to cultivate it or have it in your tank, you should include caves and tall plants where it can hide and feel secure. This will make it happier and less stressed. 

While this catfish eats all kinds of algae, the only problem with it is that it is not a hardy fish or a low-maintenance fish. You need to take good care of it. For it to thrive, you need to aerate your tank, you need to circulate the aquarium water, and you need to have many live plants. And then you need to maintain water parameters at recommended levels. Otherwise, it is fish that can get quickly stressed and die. 

The twig catfish is also territorial. However, with enough space, it does not behave aggressively. Other than it being somewhat aggressive in small tanks and needing high maintenance, it is a great algae eater. 

  1. Ghost Shrimp

Ghost Shrimp

We all know ghost shrimps. They are some of the best food for fish. They are also some of the best critters to cultivate in a small fish tank. This is because they are very interesting to look at thanks to their clear bodies. However, I bet you didn’t know that ghost shrimps are also solid algae eaters. 

They are great to use in small fish tanks where there is little algae to be removed. This is because they do not take up much space and are sufficient for algae removal in small spaces. 

To be frank, ghost shrimp are not extremely effective at removing algae like other algae eaters. However, it does not hurt to include a couple of them in your aquarium. They will clear the remaining algae that your main algae eater or eaters will leave behind or will be too big to access in small crevices, caves, and corners. 

The best thing about ghost shrimp is that they are very cheap. So if you are looking for the best and cheapest algae eaters for a nano aquarium, you should strongly consider getting a couple of ghost shrimps. 

If you do and your set up is even half good, they will automatically breed. 

  1. Amano Shrimp

Experienced aquarists love Amano shrimp more than they love other types of aquarium shrimps. This is because Amano shrimps are very effective eaters of algae and detritus. When they are in a group of four or more, they are capable of ridding aquarium water of algae within two to three days. 

Unlike the popular ghost shrimp, Amano shrimp is relatively large. It typically grows to a height of about two inches. This is what makes it capable of eating much more detritus and algae when compared to the ghost shrimp and the cherry shrimp.

Amano shrimp will serve you well but only if you keep them with nonpredatory fish (predatory fish will eat them).

All in all, Amano shrimp is the best algae eating shrimp. The only problem with this shrimp species is that it has a short lifespan (two to three years). However, if you keep it well and give it supplementary food, it will live longer. 

  1. Cherry Shrimp

This is the most unique and the most eye-catching shrimp you can have in your aquarium. It is normally bought because of its exciting colors. Experienced aquarists use it to add a bit of color and character to their planted aquariums. Experienced aquarists also use it to remove algae from their tanks. This is because the shrimp usually feeds on growing algae and its presence inhibits the growth of more algae.

In addition to removing algae from tanks, cherry shrimps are also capable of cleaning the substrate or gravel. This is because they scavenge on the substrate or gravel to look for and eat flakes and pellets and the likes. This prevents them from decomposing and making your tank water unhealthy and unsafe. In short, what I am trying to say is that this shrimp is capable of making your fish tank spotless and safe. 

  1. Cardinal Sulawesi Shrimp

This shrimp is not yet very popular in the fish keeping world. However, it is already one of the most popular shrimps among those who keep shrimps.

The shrimp grows to a maximum height of about 1-inch. This means it is very tiny and can, therefore, be used to clean algae in nano aquariums. 

In terms of beauty, the Cardinal Sulawesi Shrimp is more attractive than the red cherry shrimp. This is because it is more colorful and lively.

The fish prefers warmer temperatures of around 79 degrees because it is a tropical freshwater fish. 

If you decide to keep this shrimp in a small aquarium, it will clean algae from it with a high level of efficiency. However, if you keep it in a decent-sized tank, it will struggle to do the job.

Probably the best thing about this shrimp is that it eats microbial film and algae. So it does not need a lot in terms of supplemental food.

  1. Nerite snail

nerite snail

Nerite snails are probably the most famous algae-cleaning snails in the fish keeping world. They are popular because they have a massive appetite for algae, they are hardy critters, and they have patterns that are interesting to look at.

The fact that they have a massive appetite for algae makes them more effective at ridding algae from tanks, while the fact that they are hardy critters means they are low-maintenance and can survive in a wide range of aquarium water conditions. In fact, they are so hardy that they can thrive in both saltwater and freshwater aquariums.  

On top of being the best algae-cleaning snails in the fish keeping world, Nerite snails do not harm or eat plants. This makes them perfect for planted fish tanks.

  1. Malaysian Trumpet Snail

The Malaysian Trumpet snail is relatively small compared to Nerite snail. However, it is a pretty decent algae eater because of a couple of reasons.

First, it feeds on algae and detritus both on top and underneath the gravel. In other words, it gives algae no chance to grow and gives detritus no chance to accumulate. Not many algae-eating snails, fish, and shrimp dig below the gravel for food. So it is better than many algae-eating organisms in this regard.

Second, it is a decent algae eater because it does not damage plants. The fact that it does not damage plants makes it perfect for planted aquariums.

  1. Ramhorn snail

Ramhorn snails are considered pests by most fish keepers. However, they are very beneficial because they traditionally eat dead plants, debris, and leftover food. This prevents the organic materials from decomposing and making tanks unhealthy.

Like Nerite snails and Malaysian Trumpet snails, Ramhorn snails are totally safe for use in planted aquariums. This is because they do not harm plants. Some fish keepers worry when they see them eating leaves. However, as I have said, they are totally safe for use in planted aquariums because they do not eat leaves still attached to plants. They only eat dead leaves.

The one problem you will likely have with Ramhorn snails is that they breed quickly and can, therefore, become bothersome. You can bait them with lettuce when this happens and eliminate them from your tank.

  1. Mystery Apple snail

This snail is one of the largest algae-eating snails in the fish keeping world and it is perfect for sizeable home aquariums. Because of its big size, this snail species is capable of cleaning algae very quickly. 

However, the one problem you will have with it is that it also eats aquarium plants. So it is not the best option if you have a planted aquarium. However, if your aquarium has no plants, it is one of the best algae-eating critters you can introduce to rid it of algae.

  1. Rabbit snail

The rabbit snail is regarded as one of the most efficient algae eaters. It is native to Indonesia but it is now sold in pet stores around the world as an algae eater. It is available in many bright colors including gold and black, and it is a rather active snail. This makes it interesting to watch as it goes to work scavenging and consuming dead plants and soft algae.

Unfortunately, rabbit snails are somewhat like mystery apple snails in the sense that they do eat aquarium plants. So they are not the best option for planted aquariums. However, if you have an unplanted aquarium, you will love having one in it. 

NB: If you really want to add a rabbit snail to your planted aquarium, you should feed it with sinking wafers and blanched lettuce to make it too full to bother your plants.

  1. Chinese algae eater

This is the algae eater you are most likely to find in your local pet store in the United States. However, while it is popular across the country, it is has a couple of drawbacks. 

First, it does not eat algae only. It also eats food from regular feedings. What this means is that it will compete with your showcase fish or schooling fish for food. And when it gets enough food from your regular feedings, it will not really look for algae.

Second, it grows quite long and it is quite territorial and, therefore, not compatible with many aquarium critters including wide-bodied fish species, small fish species, and shrimps.

While this algae eater has some significant drawbacks, it is excellent for removing algae especially in big tanks with medium-sized cichlids and similar fish. This is because it is less territorial and aggressive in bigger tanks and to medium-sized cichlids.

  1. Common Pleco

The common pleco is perhaps the most widely available algae eating fish in the world. Nearly every decent pet store carries this fish species. 

When young, common plecos are perfect for removing algae from small tanks. However, they can grow as long as two feet. This means that if you buy a pleco to use as an algae remover for a small tank, you will need to re-home it in a bigger tank after a couple of years. If you do not re-home it in a bigger tank, it can even leap out of your small tank when you are not around and die of suffocation.

Common plecos are perfect for removing algae from bigger tanks because of the big size they grow to. So if you have a big tank (bigger than 75 gallons) you should strongly consider getting two or three plecos to manage algae. However, you should also note that unlike most algae eaters, plecos are high-maintenance. And when they grow, they need feeding with blanched vegetables, pellets, sinking wafers, and so on to be healthy and happy. 

As mentioned above, common plecos are perfect for big tanks. They are also perfect for tanks with large cichlids and other aggressive fish since they have bony heads and hard flanks that protect them.

  1. Rubber-lipped Pleco

The rubber lipped pleco is a very unique and interesting-looking catfish that is widely available nowadays. It likes cooler temperatures and strong currents. It also likes space. Therefore, you should only keep it in a well-functioning tank with a strong filter for strong currents and sufficient space for it to thrive. 

Many aquarists prefer rubber lipped plecos algae-eating because they are very efficient, peaceful, hardy, and feed almost exclusively on algae in the wild. A few of them in a big enough tank will be enough to clear an algae infestation in double-quick time.

However, before you buy several rubber lipped plecos for your aquarium, you should note that while they almost exclusively survive on algae in the wild, you will need to give them supplemental food in your aquarium to keep them healthy. Small pieces of vegetables and sinking wafers are sufficient to supplement the algae they will eat in your tank.

  1. Sailfin Pleco

Sailfin plecos are some of the most attractive fish species you can use as algae eaters for your tank. They are attractive because they have got great-looking fins and beautiful leopard-print bodies.

While sailfin plecos are fantastic and amazing algae eaters, they can grow as long as 2 feet in length. This means that they can only be used as algae eaters in big tanks with lots of space. So if you are a tank that is small than 75 gallons, they are not a good option for you. Another issue with sailfin plecos is that they are somewhat clumsy. So if you have potted plants, they will likely start knocking them down as they mature. They also disturb loose substrate.

While sailfin plecos do have a couple of drawbacks as explained above, they are perfect for cleaning algae in tanks with big or large fish such as pacus and oscars. This is because they are not territorial or aggressive and do not get disturbed by such fish.

If you get two or three plecos for your tank, they will probably entirely subsist on algae at first. However as time goes by and they become mature, you will need to feed them with things such as tablets, pieces of blanched vegetables, and sinking wafers to keep them strong and healthy so that they can do their jobs.

  1. American Flagfish

This fish is native to Florida. It is not the easiest fish to find in pet stores but it is a good algae eater. It only grows to a length of 2 inches so it is perfect for aquariums as small as 10-gallons in volume. 

The best thing about this fish species is that they are hardy. This means that they do not require a lot of care. However, they are somewhat aggressive to other fish and can, therefore, only be kept in tanks with swift-moving fish such as danios and more aggressive fish such as dwarf cichlids.

Other ways of getting rid of algae

If you choose the perfect algae eater for your fish tank set up, you should probably have no problem with algae after that. However, in some cases, even perfect algae eaters can struggle to deal with a high rate of algal growth. In this section, I will introduce you to some of the things you can do to minimize the growth of algae in your tank and give your algae eater or eaters an easy time to do their job. They include:

  1. Stop overfeeding your fish

It is very tempting to give food to your fish several times a day because it is very enjoyable. However, you should not do it. Because when you give too much food to your fish, it won’t eat everything and some food will end up sinking to the bottom and start decomposing. The decomposing food will become dissolved organics and it will start an algal growth.

Therefore, if you are struggling with algal growth, check how much food you are giving ends up not eaten and calibrate your feedings correctly.

  1. Do regular water changes

It is not fun to do regular water changes but it is necessary. By doing regular water changes, you will prevent the accumulation of dissolved organics and toxins. This will prevent algal grow. You should aim to replace about 20 percent of your aquarium water every seven days to reduce the growth of algae.

  1. Reduce the lighting

Algae thrive where there is much light, so if you do not have plants in your aquarium, you should minimize the amount of time light shines on your aquarium. You can do this by getting a smart LED light for your tank or buying a tank with a smart LED light. Reducing the number of hours light shines on your aquarium will reduce algal growth.


Algae are bad for aquariums. This is because they use dissolved oxygen in the water and can, therefore, suffocate fish and other oxygen-dependent organisms in the tank if they grow out of control. The good news is that they can be controlled using algae eaters. I have shared with you 20 algae eaters/ removers in this article. They are all different and perfect for different aquarium set ups. If you choose the right one for your aquarium and introduce it, you will be able to eliminate algae from your tank and keep it safe and healthy for your fish, live plants, and critters.