15 Best Algae Eaters for Freshwater Aquariums
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If you’ve dealt with algae overgrowth before, I probably don’t have to tell you how difficult is to remove it once it gets out of hand.
Even though algae can be beneficial to your tank, being a natural food source for many fish and invertebrates, often algae are a pest that should be promptly dealt with to prevent overgrowth.
Algae can change the color of the water in your tank, hinder the growth of aquarium plants by competing with them for resources, and even overtake an entire tank.
As with many things, prevention is the best cure when it comes to algae problems. And the best algae prevention? Algae eaters, for sure!
In this article, I’m going to introduce you to the best algae eaters for freshwater aquariums, so you can prevent algae overgrowth naturally.
But first, let’s see what are algae eaters and what you should absolutely know before picking an algae eater for your tank.
What are Algae Eaters?
Algae eaters known otherwise as the “clean-up crew” of aquariums are just what their name suggests – aquatic species that feed on algae either exclusively or as part of their diet.
Stocking your aquarium with these species will make sure that algae growth is kept under check and you don’t have to worry about algae getting out of control.
The aquatic species that enjoy algae as part of their diet can include fish, species of shrimp and even species of snails.
Not all algae eaters feed on all types of algae, some species enjoy a specific type of algae, other species may feed on multiple types of algae.
Things to Consider When Adding Algae Eaters to an Aquarium
When picking out algae eaters for your aquarium, you should consider:
- The type or types of algae in your aquarium;
- Tank parameters;
- Special algae eater requirements.
As I already mentioned, not all algae eaters eat all types of algae, therefore, you must figure out which algae is prevalent in your tank, so you can pick the exact algae eater that can target that specific algae.
There are hundreds of algae species, however, the most common ones that you may come across in a freshwater tank include:
- Green algae: This type of alga can overtake an entire tank and reduce the transparency of water;
- Green spot algae: Appears as green spots dotted on every surface of your aquarium. It’s usually caused by bright lights and it’s difficult to remove;
- Hair algae: Hair or thread algae appears as soft and loose green threads in your tank. Excess light or excess nutrients can cause it;
- Black beard algae: Often black or purple in color, this alga has a soft, slippery texture and grows mostly on the plants in your aquarium;
- Green dust algae: They mostly appear in tanks that are still undergoing the nitrogen cycle and form a slimy coat on the surfaces of the aquarium.
These are just some of the algae types that you may come across either during the nitrogen cycle, or long after.
When picking out the “cleaning crew” of your tank, you must also consider tank conditions.
Do your research and find out what are the water parameters enjoyed by your algae eaters and see if they match your current tank conditions.
Many algae eaters can’t live on algae in your tank alone, so you’ll probably need to supplement their diet with algae wafers, pellets or other foods they like.
Let’s see which are the best species to keep algae under control in your tank:
15 Best Algae Eaters for Your Freshwater Aquarium
The algae eaters below can be an efficient “clean-up crew” for your freshwater aquarium, helping to prevent algae overgrowth naturally:
1. Siamese Algae Eater
Although the Siamese Algae Eater is prolific at cleaning any type of algae, it has a marked appetite for black algae.
In fact, of all the algae eater species, they’re the fastest at cleaning up black algae. A small group of 4 to 5 Siamese Algae Eaters can get rid of black algae in a matter of few days.
Another thing that sets this algae eater species apart is its suitability for planted aquariums. The Siamese Algae Eater will gently clean off algae from plants without harming the plants.
I recommend them for beginners as a good option for a community aquarium to help keep algae at bay in new tanks.
They prefer tanks that are at least 30 gallons and they’re relatively easy to care for. Just to make sure to supplement their diet with algae wafers and pellets, if there aren’t enough algae in the tank.
They enjoy heavily planted tanks and usually stay in the lower parts of the tank. Make sure you pick substrate that agrees with their sensitive barbels and underbellies.
Siamese Algae Eaters are rarely aggressive, but they’re active and energetic swimmers, which means you should take care when keeping them with calmer species that may become unsettled by them.
2. Twig Catfish (Farlowella acus)
Twig Catfish require a bit more specialized care, so I don’t recommend them for beginner aquarists. They’re docile and timid creatures that are beneficial in controlling algae growth.
They feed on most types of algae, however, their diets require supplementing with other foods too.
They’re relatively small fish with a long thin body that reaches up to 4 inches. They don’t require large tanks and do best if they’re kept in pairs.
They also enjoy planted aquariums with lots of hiding spaces since they tend to be rather shy. Water parameters should be kept stable, since they’re sensitive to fluctuations.
Because of their sensitivity to water conditions it’s advisable to keep them in larger tanks, where stable tank conditions are easier to maintain.
They make good community fish provided they’re paired with peaceful species like tetras and livebearers but avoid aggressive species that might bully them.
Twig Catfish continuously graze on algae, but alga alone is not enough to sustain them. Make sure you add prepared food and lightly blanched vegetables to their diet.
3. Otocinclus Catfish
Otocinclus Catfish are one of the tiniest algae eaters, they don’t grow larger than 2 inches. They’re relatively easy to take care of and they’re peaceful fish that get along with other small bottom-feeders.
The Oto Catfish is an efficient algae-eater that will keep your tank clean along with any plants you may have. You can trust them with even the tenderest little plants.
Because they require clean water with stable parameters, I wouldn’t recommend them as a starter fish for beginners.
They enjoy being kept in groups of 5-10 and shouldn’t be kept with fish that might mistake them for food, or fish that are aggressive.
In the wild, the Oto Catfish feeds on algae and other organic substances. In captivity, their diet should be supplemented with special vegetable food, spirulina, flakes, and frozen bloodworm.
Steamed vegetables like lettuce, zucchini, squash are also a good addition to their diet.
Because of their small size, they don’t tolerate polluted water, therefore, I recommend having a good filter system and weekly water changes.
You’ll know your Oto Catfish are healthy by their high activity levels during the day and their tireless quest for soft algae in the tank.
4. Bristlenose Pleco
One of the smallest Catfish species, averaging at 3-5 inches, the Bristlenose Plecos is another excellent algae eater that you can add to your community tank of peaceful fish.
They’re recognizable after their flat, wide body and fleshy tentacles on their head. They’re available in several colors including green, gray or brown with yellow or white spots.
The Bristlenose Pleco is a bottom dweller, enjoys an herbivore diet and needs its diet supplemented with algae and spirulina wafers, flakes, granules and bloodworms.
These fish enjoy foraging in the substrate for algae and detritus, which is good news for the cleanliness of your tank.
They’re easy to keep and they can tolerate a wide range of tank conditions, making them a beginner-friendly fish.
Because they’re nocturnal fish, you should provide shadowy areas and hiding spaces where they can retreat during the day.
Make sure you house them in a tank that’s at least 25 gallons – although the bigger the better – because they produce a lot of waste, which also means you should take care to not overfeed them.
Provide a tank that’s well aerated with moderate water flow.
Mollies aren’t typically discussed as an algae eater; however, the Black Molly fish can do a great job at cleaning up hair algae in your tank.
They’re aren’t as avid algae eaters as other species in this list, but if your tank needs a little cleaning and you’re looking for an interesting species to add to your tank, this livebearer is a great choice.
Mollies, along with other livebearers, do very well in community tanks since they’re very peaceful fish that won’t cause trouble in your aquarium.
If you’re thinking about adding mollies to your community tank, make sure it’s large enough to account for the fry that will result from reproduction.
Mollies enjoy a well-lit tank with plenty of live plants that they can nibble at. They also graze on fresh algae growth, so you can count on them to keep your tank tidy.
Molly fish are omnivorous; therefore, you can feed them a variety of foods including artificial, live or frozen foods, but also foods with a large vegetable component.
The Molly fish adapts quite well to a variety of tank waters, but if you’re looking to create a perfect environment for them, you should keep temperatures around 72-78 F.
Mollies aren’t the only livebearers to graze on algae, Platies are another livebearer species that you can count on to do a little tidying up when it comes to algae.
Platies have been selectively bred to display various colors from shades of red to shades of black, green and silver.
This fish enjoys being kept in groups with others of the same species, but also with other species in a community tank. They prefer tanks in the temperature range of 72 to 77 F.
In terms of feeding, Platies are an omnivorous species, therefore, they’ll accept a variety of food: quality flake or pellets, spirulina algae, fresh veggies, brine shrimp, other fresh or frozen foods.
Because platies are capable of breeding every 30 days, make sure you’ve got enough space in the tank to accommodate the resulting fry.
You should also be careful with male to female ratio as male Platies tend to pursue females and stress them out. The best ratio is to add a single male to a group of 3 females.
Platies enjoy a densely planted tank with caves, driftwood, and rocks. They’re an excellent choice for a community tank and I recommend them even for beginners.
These are some of the best algae-eating fish species. And because fish aren’t the only algae eaters you can count on, let’s see which snails and shrimp are the best at eating algae:
7. Mystery Apple Snail
The Mystery Apple Snail is an algae eater that feeds on most types of algae, however, they have the best appetite for algae that grows on aquarium plants, glass and the substrate.
If you see a small Mystery Apple Snail, it’s most likely a baby snail, because they can grow to the size of a baseball once they reach adulthood.
This snail comes in a variety of colors; however, bright yellow is the most common color that you’ll find.
Because the Apple Snail enjoys eating plants too, it may not be the best choice for a planted aquarium unless you make sure to provide enough supplemental feeding for it.
Besides the algae that grows naturally in your tank, Apple Snails will accept all types of foods including vegetables, fish food pellets, and other fresh or frozen foods.
They’ll even feed on insects and dead fish, so don’t panic if you see an Apple Snail on a dead fish. The snail didn’t kill it, but it will feed on it since it’s there.
Although in adulthood it can fend for itself, while they’re still young, Apple Snail are an easy target for larger predatory fish or fish that like to bully other aquatic creatures.
8. Malaysian Trumpet Snail
The Malaysian Trumpet Snail is a small algae eater that doesn’t grow larger than 1 inch. They’re easily recognizable after their elongated shells that have a pointed end.
Since this type of snail does not feed on plants, you can trust them not to harm your plants while they’re grazing algae.
They enjoy all types of algae and they’ll plow the substrate for uneaten food, being a step ahead of most algae eaters in the cleaning department.
They’re good eaters and have a great appetite, so they’ll happily eat anything from fish food, bottom feeder tablets, pellets, algae wafers, detritus, all sorts of debris, and edible plant matter shed by live plants.
Some consider Trumpet Snails pets because they reproduce quickly and in large numbers. If you want to limit their reproduction, you’ll need to limit their food intake on the long run.
You can house Trumpet Snails with others of their kind such as Mystery Snails, Red Ramshorn Snails, Nerite Snails as well as other algae eating species such as shrimps.
Algae-eaters like Amano Shrimp, Red Cherry Shrimp and Ghost Shrimp are all good options for tank mates. In terms of fish species, calm and peaceful fish like the Oto Catfish and Cory Catfish are good options.
9. Rabbit Snail
The Rabbit Snail is another large alga eating snail that can reach a size of 5 inches. Its shell is shaped similarly to that of the Malaysian Trumpet Snail.
Unlike Trumpet Snails, they don’t reproduce as quickly in home aquariums, so don’t worry about your tank being overrun by Rabbit Snails.
Except from the Java Fern, which hobbyists report that Rabbit Snails are interested in, they won’t bother your other live plants, so you can add them to a planted tank.
They graze on algae, decaying plant matter, detritus. Besides these, their diet should be supplemented with foods rich in Calcium, vegetables, algae wafers, and bottom feeder tablets.
Rabbit Snails get along great with other of their kind such as Mystery Snails, Ivory Snails, Nerite Snails, Ramshorn Snails, and Malaysian Trumpet Snails.
Besides snails, the Rabbit Snail can be house with several algae eating shrimp like the Amano or Red Cherry Shrimp.
If you’re thinking of adding them to a community tank with fish, choose fish that are not in the habit of bothering snails. Avoid rough species like Cichlids, Goldfish, Loaches, or Crayfish.
10. Nerite Snail
Nerite Snails are possible the most popular pick for algae-eater snails. They’re grow a little over 1 inch and their zebra-patterned shells make them instantly recognizable.
They’re hardy snails that can tolerate a wide range of water conditions and do well both in freshwater and saltwater tanks.
Because they need saltwater to reproduce, they won’t reproduce in freshwater tanks, so you don’t need to worry about their population getting out of hand.
Nerite Snails feed on all sorts of algae and they’re efficient even against green spot algae. They’re busy and active eaters searching for food everywhere they can.
They won’t hurt your live plants, so you can go ahead and add them to planted aquariums. In fact, they enjoy planted tanks best.
If your tank produces enough algae, you don’t need to supplement their diet. If supplementation is needed, you can feed them green vegetables or algae wafers.
Most invertebrates make good tank mates for Nerite Snails and even peaceful small community fish like the Oto Catfish or the Cory Catfish can be a good tank mate.
Avoid large fish or aggressive species that may eat, kill, or bully Nerite Snails.
11. Ramshorn Snail
While some tank owners buy them as pets, Ramshorn Snails can make their way into a tank by hitching a ride on plants that are added to the tank.
This type of snail remains at around 1 inch and it got its name because its shell resembles that of a ram’s horn.
Ramshorn Snails eagerly feed on all types of algae, plant matter, leftover food, preventing them from decomposing and causing troubles in the tank.
They’re 100% safe to be added to a planted aquarium as they’re not interested in eating the plants, only the algae that grows on them.
If you want to supplement their diet, calcium-rich foods, pellets, flakes and bottom feeder tablets, fresh vegetables are all good options.
This snail will also eat dead fish and shrimp, but make sure to remove any dead fish or shrimp to avoid ammonia spikes in the tank.
Due to its small size, avoid housing it with large fish or predatory fish that will pick at them. Choose smaller and peaceful fish as tank mates and you won’t have any issues.
Like many snail species, the Ramshorn Snail reproduces fast and in large volumes, so one way you can control their population is by limiting food.
12. Ghost Shrimp
Although not the most avid algae eater shrimp on this list, the Ghost Shrimp is nonetheless an interesting and useful addition to a planted tank as they will do some algae control.
Most aquarists buy them as feeders for their fish seeing how the Ghost Shrimp is inexpensive and a very nutritious source of food for fish.
However, their transparent bodies and small size (they grow to max. 2 inches) make them a peculiar addition to a planted tank.
They’re prominent scavengers and they’ll search the tank for leftover foods and algae, making your tank cleaning tasks a lot easier.
It can cope with most water conditions provided they remain constant. They’re not fussy eaters thriving on an omnivorous diet.
It’s best to keep them with their own kind and avoid fish tanks, since they lack proper defense mechanisms (except hiding away) to be kept with other fish.
You may try housing them with small peaceful fish, but even them will mistake the shrimp fry for food.
Ghost Shrimp are easy to breed, they have a low biomass and ecological footprint and they aid in keeping nitrate levels low.
13. Bamboo Shrimp
The Bamboo Shrimp is a popular species of freshwater algae-eating shrimp that grows to around 2-3 inches in length.
They are reddish-brown and feature a white stripe. They enjoy 20-gallon tanks or larger.
Like many other algae-eaters on this list, the Bamboo Shrimp enjoys a planted aquarium with lots of live plants.
They enjoy positioning themselves of the filter sponge and intercept food matter that would otherwise end up in the filter.
Like many other shrimp species, the Bamboo Shrimp lives 1-2 years, maybe a bit more if tank conditions are good.
In an established aquarium, this shrimp will feed on just about any food it comes across — micro-algae, plant debris, particles of fish food. As a food supplement, pulverized algae wafers are a good choice.
Bamboo Shrimp are very peaceful, they can neither attack or defend themselves. Compatible tank mates include small sized peaceful fish.
They can also live with a large variety of shrimp and snails including the algae-eater shrimp and snails that I discuss in this article.
14. Amano Shrimp
If you plan on setting up a planted tank, Amano Shrimp are a great asset if you’re looking to keep algae under control in a natural way.
The Amano Shrimp reaches sizes of 2 inches and it’s a powerhouse when it comes to feeding on algae.
They have a translucent light grey body, but shades of green, brown or even red are also common.
They do best in groups of 3 or 4 and you can add them to a peaceful community tank inhabited by smaller species.
Naturally, you should avoid housing them with large, predatory fish like Goldfish or Cichlids. You can keep them with other freshwater shrimp and snail species.
They have a lifespan of 2 to 3 years. They enjoy feeding on soft algae, edible plant matter, and other sources like shrimp pellets, fish food flakes, algae wafers, and green veggies.
They’re active eaters and they usually go about their business searching the tank for food.
They’ll feed on dead fish and dead snails too, however, make sure to remove any dead fish to avoid toxins getting released into the aquarium.
15. Cherry Shrimp
My favorite shrimp species, but also the most spectacular on this list, the Red Cherry Shrimp was named after its bright red color that contrasts exceptionally well with green plants.
I also enjoy them because they’re low maintenance and self-sufficient. Unfortunately, they only live about a year or so, so they’re not for everyone.
Cherry Shrimp graze on soft green algae or brown algae and pick up leftover food, preventing them from decomposing and keeping toxin levels low.
Other foods that they’ll eat include fish flakes, shrimp pellets, algae wafers, etc.
Since they’re small and have no way to defend themselves, keeping them with large, predatory fish is out of the question.
Although they do well with other shrimp species, I don’t recommend housing them with shrimp they can reproduce with because the resulting offspring will be weak.
If you’re planning on breeding Cherry Shrimp, make sure you provide plants with large leaves that can serve as a hiding spot for the shrimp fry.
If you’re considering keeping Cherry Shrimp, go with a species-only tank or add a few to a community tank with small, peaceful fish or snails.
And with this, I conclude my list of the best algae eaters that I recommend for freshwater tanks. Next, let’s see how else you can prevent algae from getting out of control.
Tips to Prevent Algae Growth
As you can see, each species of algae-eater has its own particularities and choosing one for your tank can depend on various factors – type of algae, tank conditions, and tank mates.
Algae-eaters shouldn’t be the first line of defense against algae, instead they should be part of a series of preventative measures you take to prevent algae from overtaking the tank:
- Keep the tank clean by doing regular water changes:
Weekly or bi-weekly water changes are necessary if you want to remove toxins and replenish water with healthy trace elements. This will help slow down algae growth in the tank.
- Adjust lighting conditions:
Sometimes, too much light is the cause behind excessive algae growth. Try cutting down on the amount of time you run your lights for and see if they’re any changes.
- Avoid overfeeding your stock:
Too much food that goes uneaten or overfeeding fish that produce a lot of waste can be another reason why algae can grow out of control in your aquarium.
A good way to keep algae under control is too look at your feeding pattern and cut down on feeding when it’s excessive.
I’m not saying you should ever starve your fish, just make sure they don’t regularly leave food uneaten in the tank.
If you regularly notice decaying food in your tank, try cutting down on feedings and see how it impacts algae growth.
- Invest in quality filtration:
If filtration is no good in your aquarium, don’t be surprised if you notice algae in your tank.
Make sure you choose the right filter for the size of tank you have.
For example, for tanks under 50 gallons a hang-on-back filter can be a good choice, while for tanks over 50 gallons, a canister filter is better.
The algae eaters I discuss in this article should be part of any aquarium as a means of algae prevention and control.
You shouldn’t view these species as miracle workers and you shouldn’t relax your tank cleaning habits just because you’ve added some algae-eaters to the tank.
With that said, I hope the advice in this article will help you keep your aquarium nice and clean, and you won’t have to deal with any aggressive algae problems.