Siamese Algae Eater: A Little Workhorse

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The Siamese Algae Eater is a freshwater fish known for its exceptional ability to control algae in aquariums.

This versatile swimmer not only enhances the visual appeal of your tank but also serves as a natural cleaner.

It’s a must-have for anyone looking to maintain a balanced aquatic environment.

Quick Facts

Scientific NameCrossocheilus oblongus
OriginSoutheast Asia (Thailand, Malaysia)
LifespanUp to 10 years
Size6 inches
Minimum Tank Size20 gallons
Tank SetupFreshwater, heavily planted
Water Temperature75-80°F
Water pH6.5-7.5 (tolerant up to 6.0-8.0)
Water Hardness5-15 dH
CompatibilityPeaceful community fish
BehaviorBottom-dweller, active, social
BreedingDifficult, usually requires hormonal assistance


The Siamese Algae Eater, scientifically known as Crossocheilus siamensis, is a popular fish among aquarium enthusiasts.

This friendly and hardy fish is highly sought after for its ability to control and eliminate algae in freshwater tanks.

In this comprehensive guide, I will provide you with all the information you need to successfully keep and care for Siamese Algae Eaters in your own aquarium.

Species Summary

The Siamese Algae Eater, native to Southeast Asia, can be found in freshwater rivers and streams.

This species is known for its hardiness, making it suitable for aquarium enthusiasts of all skill levels.

With their ease of care and ability to thrive in various conditions, these fish are a great choice for both beginners and experienced hobbyists.


Siamese Algae Eaters have sleek and streamlined bodies, with pointed snouts and slender fins.

They typically have a dark black or brown coloration on their back, fading to a lighter shade on their belly.

These fish are adorned with a distinctive horizontal stripe that runs along their body, from the head to the tail.

Males and females of the species share a similar appearance, making it difficult to distinguish between the two.

However, during the breeding season, the males may develop a more vibrant coloration and display a slight red tinge on their fins.

These fish can reach an average size of 4-6 inches (10-15 cm) in captivity.

But, their size can vary depending on the quality of care and the environment they are kept in.

Siamese Algae Eater Care


The Siamese Algae Eater has an average lifespan of 5-8 years when kept in optimal conditions.

To help extend their lifespan, provide them with a well-maintained and suitable aquarium environment.

Proper nutrition, water quality, and a stress-free environment are key factors in promoting a long and healthy life for these fish.

Behavior & Temperament

Siamese Algae Eaters are known for their peaceful temperament.

They are generally non-aggressive towards other fish and can be kept in a community tank with a variety of tank mates.

It’s worth noting though that these fish may display territorial behavior towards their own species, especially if the tank is smaller or lacks hiding spaces.

When it comes to their swimming behavior, Siamese Algae Eaters are active and agile swimmers.

They prefer to occupy the lower and middle levels of the aquarium, constantly searching for algae to feed on.

These fish are excellent jumpers, so it’s important to have a securely fitted lid on their tank to prevent any accidental escapes.


Taking care of Siamese Algae Eaters is relatively straightforward, making them a great choice for beginner fishkeepers.

Tank Size

A minimum tank size of 20 gallons is recommended for keeping Siamese Algae Eaters.

This size provides enough space for these active swimmers to explore and thrive.

A larger tank helps reduce territorial behavior and enables better water quality management.

Siamese Algae Eater Tank Size

Water Parameters

Siamese Algae Eaters prefer a well-maintained aquarium with stable water conditions. The following table outlines the ideal water parameters for these fish:

ParameterIdeal Range
Temperature75-80°F (24-27°C)
Hardness5-15 dGH

Regular monitoring and appropriate adjustments should be made to ensure these parameters remain within the recommended ranges.

What To Put Inside Their Tank

Siamese Algae Eaters originate from freshwater rivers and streams in Southeast Asia.

To replicate their natural habitat in a home aquarium, provide suitable plants, substrate, and decor.

Plants such as Java Fern, Anubias, and Hornwort are excellent choices, as they not only provide hiding spots but also aid in maintaining water quality.

A sandy or fine-grained substrate is preferred, as it mimics the sandy riverbeds where these fish are often found.

Adding driftwood and rocks will also enhance their natural environment and provide additional hiding places.

Water flow should be moderate to mimic the natural conditions these fish are accustomed to.

Using a filter or adding a powerhead can help create the desired water flow, ensuring the well-being of your Siamese Algae Eaters.

Food & Diet

Siamese Algae Eaters are primarily herbivorous and have a voracious appetite for algae.

They are highly effective in controlling and consuming various types of algae in the aquarium.

In addition to algae, their diet should include high-quality sinking pellets or flakes specifically designed for herbivorous fish.

These can be supplemented with blanched vegetables such as zucchini, spinach, or cucumber.

You need to provide a varied diet to promote optimal health and prevent nutritional deficiencies.

Tank Mates Siamese Algae Eater

Tank Mates

Siamese Algae Eaters can be kept with a wide range of tank mates due to their peaceful nature.

Suitable tank mates include peaceful community fish such as Tetras, Guppies, and Corydoras catfish.

Avoid pairing them with aggressive or fin-nipping species, as this may lead to stress or aggression towards the Siamese Algae Eaters.


Breeding Siamese Algae Eaters in the home aquarium can be challenging.

These fish are known to spawn in fast-flowing rivers and reproduce through external fertilization.

Recreating these conditions in a home aquarium can be difficult, but not impossible.

To encourage breeding, provide a larger tank with strong water flow, preferably through the use of a powerhead.

Maintain optimal temperature and water parameters.

Introducing a small group of Siamese Algae Eaters can also increase the chances of breeding.

The resulting fry are extremely delicate and require specialized care and feeding to ensure their survival.

Breeding Siamese Algae Eaters

Why You Should Consider This Fish

Siamese Algae Eaters are not only beautiful but also highly beneficial for maintaining a healthy and algae-free aquarium.

Their hardy nature, peaceful temperament, and efficient algae-eating abilities make them an excellent addition to any freshwater tank.

Whether you are a beginner or an experienced aquarist, the Siamese Algae Eater is a fantastic choice for keeping your aquarium clean and vibrant.


Are Siamese Algae Eaters compatible with other algae-eating fish?

Yes, Siamese Algae Eaters can coexist peacefully with other algae-eating fish, such as Otocinclus catfish or Bristlenose Plecos. It’s important to provide enough algae or suitable alternative food options to prevent competition or aggression.

Can Siamese Algae Eaters live with shrimp or snails?

Siamese Algae Eaters generally do not pose a threat to shrimp or snails. However, caution should be exercised if keeping small or delicate species, as the Siamese Algae Eaters may accidentally harm them while searching for food.

How many Siamese Algae Eaters should be kept together?

Siamese Algae Eaters are shoaling fish and should ideally be kept in a group of at least 3-5 individuals. This helps to reduce aggression and improves their overall well-being.

Do Siamese Algae Eaters require a specific lighting setup?

Siamese Algae Eaters do not have specific lighting requirements. However, it’s important to provide suitable lighting to support the growth of live plants in the aquarium, which in turn helps maintain water quality.

How can I control the growth of algae in my tank without Siamese Algae Eaters?

If Siamese Algae Eaters are not an option for your tank, regular maintenance practices such as regular water changes, controlling nutrient levels, and maintaining a proper lighting schedule can help control algae growth. Additionally, introducing other algae-eating species like snails or shrimp can provide natural algae control.

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Irma Bense is the founder of She has over 42 years of experience in keeping fish.She has kept both freshwater and saltwater fish through the years.She has extensive knowledge in breeding numerous species of fish from Show Guppies, Cory Catfish, German Blue Rams to Apistogrammas.You can learn more about Irma on the 'About' page.

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