Looking for a clean-up crew to help control the growth of algae in your freshwater aquarium?
In this article, you’re going to learn how to choose the best algae eater for your aquarium, as well as discovering my favourite algae eaters for your tank.
Let’s get started.
What is an Algae Eater?
Algae is a common problem in freshwater aquariums but getting rid of it may be as simple as stocking your tank with a few hungry algae munchers.
The term algae eater (also sometimes referred to as “clean up crew”), is used to describe species that feed on algae, either exclusively or as part of their natural diet.
An algae eater can be a species of fish or even an invertebrate such as a snail or species of shrimp.
Some algae eaters feed on specific types of algae while others graze more openly on multiple different types.
Others may also feed on aquarium plants, so be careful about adding algae eaters to a planted aquarium.
What to Consider Before Choosing one for your Aquarium
Before choosing an algae eater for your tank there are several things you need to consider. First and foremost, what kind of algae do you have in your tank?
If you are dealing with a specific type of algae, your best bet is to choose an algae eater that will feed on that type of algae.
For tanks with more large-scale algae problems, it may help to add two or three different types of algae eater to your tank (as long as they’re able to live with each other).
But what are the different types of algae you might find in your tank?
Here’s a quick overview:
- Hair algae – Also known as filamentous or thread algae, hair algae is light green and grows in wispy filaments. It grows quickly and attaches to any tank surface.
- Brown algae – Also known as diatoms, brown algae are single-celled algae that is brown in color. This algae starts out as a dusting over tank surfaces then turns into a thick mat over the course of several days.
- Brown slime algae – Also known as dinoflagellates, brown slime algae is symbiotic – it provides nutrients for invertebrates like snails but can also take over the tank.
- Blue green algae – Also known as cyanobacteria, blue green algae is actually pinkish-red in color, in most cases. It is single-celled and starts with a spot or two but quickly spreads.
- Black beard algae – Often dark purple or black in color, black beard algae usually grows on aquarium plants.
- Green spot algae – This type of algae grows in tanks with bright lighting and it can be hard to remove. It typically grows on tank walls and slow-growing plants.
- Green algae – This type of algae is also known as an algae bloom and it can happen if you do not let your tank cycle properly or if the lighting is too bright.
If you’d like a more indepth breakdown for all the different types of algae, you can check out our algae guide here.
When considering the options for algae eaters, you also need to think about the conditions in your tank.
Algae-eating fish, snails, and shrimp all have their own requirements for tank parameters so you’ll either need to choose one that is compatible with the conditions in your tank or alter your tank conditions to suit your new algae eater.
Finally, you need to consider how easy it is to care for the algae eater.
Some species require more care than others, particularly when it comes to supplemental feeding.
Unless your tank is producing a lot of algae, you will probably need to supplement your algae eater’s diet with some kind of vegetable or with algae wafers and pellets.
The Best Freshwater Fish to Eat and Control Algae in your Aquarium
Some freshwater fish feed on plant-based foods while others are carnivorous.
Algae eating fish are herbivorous by diet, so they are likely to accept plant foods in addition to feeding on algae.
Let’s go over your options:
1. Siamese Algae Eater (Scientific Name: Crossocheilus oblongus)
The Siamese algae eater is one of the most effective algae-eating fish because it feeds on a variety of different types of algae.
These algae eaters are also great because they will eat some of the algae that other algae eaters ignore like black beard algae.
This species is also fairly peaceful and relatively easy to care for so they may be a good choice for beginner aquarium hobbyists to help control algae in a new tank.
Siamese algae eaters need a tank size no smaller than 30 gallons and they prefer a pH between 6.5 and 7.0 with a temperature between 75°F and 79°F.
These fish can be housed in community tanks and they are moderately easy to care for as long as they have enough algae to eat.
It isn’t a bad idea to supplement their feeding with algae wafers or pellets to make sure they don’t go hungry.
2. Chinese Algae Eater (Scientific Name: Gyrinocheilos aymonieri)
The Chinese algae eater is easy to care for and does well in tanks at least 30 gallons in capacity.
These fish do grow fairly large, however – up to 10 inches – and they tend to become more aggressive as they grow.
For this reason, you should be careful about keeping them in a tank with delicate species of fish.
On the other side of the issue, their aggression can be a good thing – they are one of the only algae eaters that can be kept with large and semi-aggressive species like cichlids.
Chinese algae eaters prefer a pH between 6.8 and 7.4 with a KH between 8 and 10. They prefer warmer water temperatures and they require an herbivorous diet to supplement their feeding on algae.
They are not one of the most effective algae eaters on the list because they tend to grow lazy as they get bigger, but they may feed on different algae types while young.
You should also provide this species with hiding places like hollow logs or rock caves.
3. Twig Catfish (Scientific Name: Rineloricaria lanceolate)
These fish have long, thin bodies and they grow to about 4 inches in length.
Twig catfish are docile, so they’re compatible with peaceful species such as tetras and livebearers, though they can be bullied by cichlids and larger fish.
Though they were once fairly uncommon, these fish are becoming increasingly more available as more aquarium hobbyists are learning about their benefits.
These fish are best kept in pairs and require a tank size of at least 12 gallons.
They prefer moderately soft water with a pH between 6.0 and 8.0 – they do not take well to changes in water chemistry and they will feed on most types of algae but still require supplemental feeding.
Out of the algae eating fish on this list, the twig catfish is one that requires more specialized care than the others. They also need places to hide in the tank because they tend to be very shy.
4. Otocinclus Catfish (Scientific Name: Otocinclus sp.)
One of the smallest algae eaters on this list, the otocinclus catfish grows to a maximum of 2 inches (and one of my favorites :D).
These fish are similar in appearance to the larger Chinese algae eater, but they are much more peaceful.
This species does well in community tanks and gets along with other bottom-feeders, but they shouldn’t be kept with large or aggressive species like cichlids.
Otocinclus catfish are moderately easy to care for, but they do need a large tank of at least 30 gallons to ensure they have enough algae to feed on and because they are best kept in schools.
They prefer a pH between 6.5 and 7.5 but can tolerate some variety in water chemistry. These fish are particularly good at removing brown algae and they eat it quickly, before it becomes a problem in your tank.
You can check out our detailed guide on Otocinclus care here.
5. Whiptail Catfish (Scientific Name: Rineloricaria sp.)
A species of armored catfish, the whiptail catfish is moderately easy to care for and has a peaceful temperament.
These fish come in neutral colors like black and tan, and they grow up to 6 inches in length, so they require a tank at least 50 gallons in capacity.
The whiptail catfish is omnivorous, so in addition to feeding on algae it will also feed on detritus such as uneaten fish food.
These fish prefer a KH between 4 and 8 with pH in the 6.5 to 7.0 range. Their preferred water temperature is between 73°F and 79°F since they come from the tropics in South America.
6. Bristlenose Pleco (Scientific Name: Ancistrus temminckii)
Also known as the bristlenose catfish, this species is named for the whisker-like projections on its snout.
These fish are easy to care for, though they do grow to a length around 5 inches. Bristlenose plecos are compatible with most peaceful species and they will tolerate a range of tank conditions.
However, they prefer a pH between 6.5 and 7.5 with slightly hard to slightly soft water.
The minimum recommended tank size is 20 gallons and they generally require supplemental feeding with algae wafers, though they will feed on green spot algae.
7. Mollies (Scientific Name: Poecilia sphenops)
Though they may not feed on algae as some of the other fish on this list, mollies and other livebearers will feed on algae from time to time if it is available.
Other livebearers you might consider are swordtails and platies.
Swordtails are unique because they come in a variety of different colors and you can tell the sexes apart because males have a long sword-like projection at the base of their tail. Platies also come in many different colors and patterns.
Mollies and other livebearers are very peaceful fish and they do well in community tanks at least 20 gallons in size, or larger depending how many you have.
On average, mollies grow 2 to 4 inches in length and they prefer a pH between 7.5 and 8.5.
Mollies can also do well in slightly brackish conditions, so consider adding a little aquarium salt to your tank (but always consider others in your tank before adding anything).
One thing to keep in mind with mollies and other livebearers is that they reproduce quickly – make sure you have enough space to accommodate them.
Algae Eating Freshwater Snails you can try
You may think of snails as a nuisance in the freshwater tank, and, while that’s certainly true of some species, larger snails can work wonders on unwanted algae.
Here are my top five freshwater snails that eat algae:
1. Nerite Snail (Scientific Name: Neritina sp.)
Known for the zebra-like pattern on their shells, nerite snails are one of the most popular species of algae-eating snails.
These snails eat every type of algae, even the tougher types like green spot algae, and they work very quickly.
One thing to be mindful of is that these snails have a hard time turning over if they should fall on their back, so be careful when handling them.
Nerite snails grow to just over an inch in length so they are fairly small – this means you need to be careful about keeping them with large and predatory fish.
These snails prefer a pH between 6.5 and 8.5 with a KH in the 12 to 18 range. They can tolerate a wide range of water temperatures from 65°F to 85°F, so they can adapt to the conditions already in your tank.
2. Ramshorn Snail (Scientific Name: Planorbidae)
Named for the shape of their shell (it is shaped like a ram’s horn), these snails feed on a variety of different types of algae as well as uneaten fish food and decaying plant matter.
They do not, however, eat live plants and they do well with smaller and more peaceful species of fish – they can become a target for cichlids, loaches, and other predatory fish.
Ramshorn snails grow up to an inch in size and they prefer neutral tank water around 7.0 pH. They can be kept singly, with other ramshorn snails, or with nerite snails.
Ramshorn snails come in two primary color schemes – black and red. The red coloration is a bright red and it is interesting to note that their skin is the same color as their blood.
3. Mystery Apple Snail (Scientific Name: Pomacea bridgesii)
Because they are typically sold as babies, many people do not realize just how large the mystery apple snail can grow (up to the size of a baseball).
These snails come in various colors, though bright yellow is the most common, and they feed on most types of algae. Their favorites, however, are plant algae, glass algae, and substrate algae.
Mystery apple snails are able to fend for themselves, though they may be a target for predatory fish when they are very small.
They prefer warmer tank water and they will feed on live plants, so make sure you give them supplemental feeding if you keep them in a planted tank.
4. Malaysian Trumpet Snail (Scientific Name: Melanoides tuberculata)
One of the smallest algae eaters on this list, the Malaysian trumpet snail grows under 1 inch in length.
These snails have long shells that come to a point and they can be found in a variety of different colors. Malaysian trumpet snails feed on several different types of algae, but they don’t feed on plants, so they’re a safe addition to your planted tank.
Malaysian trumpet snails need at least 10 gallons for tank size and prefer a pH between 7.0 and 7.5. They are very easy to care for and do well in community tanks with peaceful species, though be careful because they reproduce quickly.
This species of snail also tends to plow through the substrate in search of food, so be careful about keeping them with rooted plants.
5. Rabbit Snail (Scientific Name: Tylomelania app.)
The rabbit snail is one of the larger species of algae-eating snails, growing up to 5 inches in length.
These snails have long, pointed shells similar to the Malaysian trumpet snail and they come in various shades of yellow and brown.
This species generally doesn’t feed on live aquarium plants with the exception of java fern, so be mindful of that.
Rabbit snails need at least 30 gallons of tank size and they prefer slightly cooler water temperatures between 68°F and 74°F.
These snails are moderately easy to care for and they prefer a pH between 6.5 and 7.5 with a KH between 2 and 15.
Rabbit snails consume decaying plant matter and other detritus in addition to algae and they do reproduce in the home aquarium, but not very quickly.
Algae Hungry Freshwater Shrimp for your Tank
Freshwater shrimp make an excellent addition to the “cleanup crew” in your tank.
Not only do they feed on detritus like uneaten fish food and decaying plant matter, but some species will also feed on algae.
Just be careful about adding shrimp to your tank because larger fish may eat them.
1. Amano Shrimp (Scientific Name: Caridina multidentata)
These shrimp are easy to care for and because they only grow up to 2 inches in length, they can be kept in fairly small aquariums.
Amano shrimp require soft to slightly hard water in the 6.5 to 7.5 pH range. They also prefer warmer water temperatures between 72°F and 78°F, though they are adaptable as long as their other needs are met.
This species does well in groups of three or more and they can be kept in tanks with small to medium-sized peaceful fish, though they may be a target for large and aggressive fish like cichlids and goldfish.
In addition to feeding on algae, these shrimps will also feed on uneaten fish food and other detritus.
2. Cherry Shrimp (Scientific Name: Neocardidina denticulata sinensis)
Named for their bright red color, cherry shrimp are a great addition to your freshwater cleanup crew, but they are also ornamental.
These shrimp do best in groups of 2 to 4 can they can be kept in tanks at least 10 gallons in capacity. They prefer a pH range of 6.0 to 8.0 and a KH of 3 to 10 with a wide temperature range between 60°F and 80°F.
Cherry shrimp are easy to care for as long as they have algae to feed on, though they may consume other detritus as well.
This species tends to thrive in planted tanks and they can get along with other peaceful tank inhabitants, though they may become prey for larger and carnivorous fish like puffers and loaches. It is best to keep them with smaller fish.
3. Ghost Shrimp (Scientific Name: Palaemonetes sp.)
Aptly named for their see-through bodies, ghost shrimp are not quite as effective as amano shrimp or cherry shrimp in the algae-eating department, but they will certainly help if you have an algae problem.
Though their bodies are transparent, they have an orange or yellow spot in the middle of the tail that makes them easy to identify.
Ghost shrimp grow up to 2 inches in length and they are easy to care for in a 10-gallon tank with a temperature range of 68°F to 85°F, a KH between 3 and 10, and a pH between 6.5 and 8.0.
These shrimp are peaceful by nature and they make excellent scavengers for a community tank when kept with other small and non-aggressive species.
4. Bamboo Shrimp (Scientific Name: Atyopsis moluccensis)
Bamboo shrimp are reddish-brown in color with a white stripe. These shrimps grow between 2 and 3 inches in length, so they’re one of the larger species of algae-eating shrimp on this list.
They require a tank size of at least 20 gallons with a pH between 7.0 and 7.5, slightly hard water, and high water quality.
Bamboo shrimp are fairly easy to care for as long as they have plenty of algae and detritus to feed on, though you may still want to supplement their feeding with crushed algae wafers just in case.
These shrimp are peaceful by nature so they do well in the community tank, though they may become prey to larger and carnivorous species.
Generally speaking, however, they do fine with smaller fish.
Summary: Which is The Best Algae Eater?
When it comes to the best algae eater, there is no one-size-fits-all.
The truth is, the algae eater that’s best for your tank will depend on the factors discussed above – the type of algae you have, the size and conditions in your tank, and any other tank inhabitants you may have already.
The best thing you can do is to research the options and choose the one that seems like the best fit for your specific aquarium.
Let me know if you have any questions in the comments.