Siamese Algae Eater: The Complete Care Guide (2024)

Siamese Algae Eater in Freshwater Aquarium
Featured Image – Siamese Algae Eater
Dr. Mollie Newton
Published by Dr. Mollie Newton PHD| Senior Editor
Last updated: April 12, 2024
Review Process and Evaluation Criteria
We conduct hands-on testing for all the products highlighted in our reviews and guides. Through anonymous product ordering and involving an independent team of testers, we gather direct experience to offer recommendations backed by data.

Are you grappling with an accelerated growth of algae in your aquarium? Struggling to find a fish that can consume hair algae, black beard algae, and green algae? Allow me to introduce you to the solution – the Siamese algae eater!

Article Summary

  • Siamese Algae Eater is a popular freshwater fish known for its excellent algae-eating capabilities.
  • The recommended tank size for Siamese Algae Eaters is a minimum of 30 gallons, with additional space needed for each additional fish.
  • Common diseases that may affect Siamese Algae Eaters include Ich, fin/tail rot, and bloating; maintaining a clean tank and feeding high-quality food can help prevent these issues.

This interesting fish is the aquarium hobby’s leading algae eater and is the perfect addition to any community freshwater tank. In this article, find out everything you need to know about caring for one of these fantastic creatures.

Species Overview

Common namesSiamese algae eater, SAE
Scientific nameCrossocheilus siamensis
SpeciesC. siamensis
Size6 inches
Lifespan10 years
DistributionSoutheast Asia
ColorBeige with a thick black stripe and lighter colored belly
Temperament Peaceful
Minimum tank size30 gallons
Place in tankBottom
Care levelEasy

History and Background

Endemic to the tropical waters of Asia the siamese algae eater is elusive in the wild, but a favorite in the aquarium hobby.


Originating in Southeast Asia this fish species is primarily found in Thailand and Cambodia in the Chao Phraya and Mekong river basins. They are also found in the Malay Peninsula. They live in fast flowing streams and rivers.


During heavy rains and monsoons these fish can also be found in the flooded forests of the region.

Are algae eaters easy to keep alive?

Yes, as long as you are ensuring that their basic needs are met SAE’s are fairly low maintenance and will mostly keep to themselves.

Are Siamese algae eaters good at eating algae?

Yes! Widely regarded as one of the best algae eaters which is why many aquarists are fond of them. They are one of the few fish species that will consume hair algae, red algae, and black beard algae making them an especially valued part of tank clean-up crew.


Siamese Algae Eater In A Planted Aquarium
Siamese Algae Eater In A Planted Aquarium

These peaceful fish may not look like up but they are one of the most popular algae eating freshwater fish in the aquarium hobby.

What do siamese algae eater look like

Siamese algae eaters have long, skinny bodies that are beige or pale grey in coloring. The true siamese algae eater has a black stripe that runs lengthwise the full length of their body. Their caudal fin is semi-transparent and they possess a small sucker-like mouth with small barbs under it.

These are one of the few fish that don’t have a swim bladder, meaning that they have to constantly move or risk sinking, this accounts for their active nature.

Siamese algae eaters vs Siamese flying fox fish 

The siamese flying fox is often mistaken for their closely related cousins the siamese algae eater (so often that it’s earned the name false siamese algae eater!). Although these two fish species look extremely similar in terms of body shape, markings, and coloration, flying foxes do not eat algae nearly as efficiently.

For a tank that is overgrown with algae, this could make a huge difference. Here’s a few features to help you spot the difference between the two fish.

Siamese algae eaterFlying fox
Black stripe along the entire length of the body
Solid color above and below the strip
1 set of barbels
Black stripe doesn’t go all the way to the tail fin
Narrow lighter colored band above black stripe
Two sets of barbels


Siamese algae eaters are often mistaken for chinese algae eaters as well. However these fish are starkly different. Whereas the SAE is silver/gray, and only grows up to 6 inches, the chinese algae eater is golden/beige and can grow up to 11 inches. The Chinese variety is also very territorial compared to the SAE’s peaceful nature.

How to tell the difference between a male and female Siamese Algae Eater?

The only visible difference between males and females of this species is that the females tend to be slightly larger in size when viewed from above. Because of this it is hard to identify gender before the fish reach full size at around 3 years of age.

Siamese algae eater size

SAE’s grow up to 6 inches in optimum conditions.

How big does a siamese algae eater get 

This fish species will grow up to 6 inches. However, it is a very slow grower and you can expect it to take roughly two years for them to reach their full length. Juveniles are generally sold when they are 1.5 to 2 inches or 6-8 months old. 

Temperament and Tankmates

A school of Blackline Tetra with Siamese algae eater
A school of Blackline Tetra with Siamese algae eater

Most fish will leave your siamese algae eater alone provided they have enough space in the tank. However, these fish are relentless when they find an algae patch and will push any fish out of their way in their efforts to get to it.

Siamese algae eater aggressive? 

No, true siamese algae eaters are peaceful bottom dwellers that do well in community tanks with other species. The only situation when you might see some aggression is when males become territorial. This normally only happens when you are keeping small schools that require a hierarchy.

Until your siamese algae eaters establish a pecking order they might nip at each other, if any of these interactions seem overly aggressive or cause physical injury you should immediately separate the offenders.


The Siamese flying fox is aggressive, if you notice one fish in your school being a bully check and make sure you haven’t misidentified it.

Are Siamese algae eaters fin nippers? 

No, your siamese algae eater will likely be too busy scavenging for algae to pay attention to any other fish.

What eats a siamese algae eater? 

Any fish that is larger than siamese algae eaters and is aggressive can potentially eat them. SAE’s are peaceful and don’t have any defense mechanisms which is why it’s important to choose non-aggressive tank mates.

What fish can live with siamese algae eaters?

Most fish species are compatible with siamese algae eaters, however they should be housed with fish of similar size to ensure little aggression. If being housed with other bottom dwelling fish or other algae eaters be sure that the other fish is not territorial.

Top 5 compatible tank mates

  1. Guppies – While they are much smaller than the siamese algae eaters, guppies can be kept in a group of 6 or more and are active fish and fast swimmers.
  2. Tetras – Neon tetras in particular make excellent tank mates as they are unproblematic and one of the most social community fish. These active fish have the speed and group size to discourage any fish from nibbling on their fins. They also make up for the colors your siamese algae eaters lack with their vibrant coloring.
  3. Angelfish – Keeping these two fish together is controversial because angelfish can be aggressive, and mostly works because they occupy different areas of the tank. However, they are good if you don’t want to keep small, schooling fish.
  4. Docile gouramis – Gouramis can be ornery, however docile ones such as the pearl, sparkling, or honey gourami are generally peaceful species and are of close enough size that your algae eater won’t bother them. 
  5. Swordtails – While smaller than siamese algae eaters, swordtails enjoy being housed in large groups meaning that your algae eaters will likely leave them alone. Especially in a planted aquarium with lots of hiding spots.

Siamese algae eaters are schooling fish which means the best tank mates are those of their own kind. You should keep these fish in groups of 5 or 6. But remember that overstocking can make your tank messier rather than cleaner.

Other potential tank mates include Mollies, Danios, African Butterfly fish, barbs, and rasboras. 


As siamese algae eaters like slightly acidic tank water be careful adding snails as tank mates. Acidic tank water can lead to the breakdown of shells.

Tank Requirements 

Planted Aquarium
Planted Aquarium

If this is your first fish you should review our guides on filters, heaters, and tank recommendations to ensure that you fully understand the needs of your siamese algae eater. I discuss specific parameters below, but the above guides will give you a general overview of fish tank maintenance and setup.

What size should my tank be?

If you are only keeping one siamese algae eater you should have a minimum tank size of 30 gallons. However since these fish prefer to be in groups, you should add roughly 10 gallons for every additional siamese algae eater. The reasoning behind such a large tank size is that as bottom dwelling fish that like to swim siamese algae eaters need a tank with a large bottom to explore.


Regardless of the tank setup you decide on, your aquarium should have a lid as SAE’s are known to be escape artists and jump out of tanks.

Water Parameters

Tank Size>30 gallons
Water TypeFreshwater
Water Temperature70-79
Water pH6.5-7.5
Water hardness4-12 dGH


The siamese algae eater fish can tolerate a wide range of water hardness, however if you plan on keeping live aquatic vegetation you should be aware that most of them prefer a hardness range between 4-8 dGH.

How should I set up my tank?

Tank setup should replicate the natural environment of your fish. Having small tunnels made of hollowed out logs, large plant leaves, and fast water flow provided by a pump will help make your fish feel at home.

What substrate should I use?

Sand, fine gravel, or large smooth rocks are the best type of substrate for your algae eater. As they spend a majority of their time along the bottom of the tank to eat algae you should ensure that none of your substrate has sharp edges.

Do I need a filter?

Your siamese algae eaters will still need a filter. Even though they are cleaning algae and other decaying matter they are making waste of their own and will need a filter to help make the water cleaner. Additionally, in their natural habitat there is constantly circulating water creating flow and current, without this circulation your fish would be unhappy.

Do I need an air pump?

Like mentioned earlier, siamese algae eaters live in bodies of water with fast moving current. The addition of a pump can help circulate water throughout your tank. Additionally, if you plan to add plants to your tank this high level of circulation is necessary to ensure all species are receiving enough oxygen.

Should I add a heater?

Since siamese algae eaters need tropical tank conditions you will likely need an aquarium heater to maintain proper water temperature.

What is the best aquarium lighting for siamese algae eaters?

This fish enjoys a well-lit tank, which is helpful for both algal growth and live plants housed in the tank.

Should I add live plants to my aquarium?

This fish enjoys a heavy planted tank that replicates the plant matter of its native environment. Additionally, plants with large leaves provide additional surfaces for algae to grow on making your siamese algae eater even happier.

To compliment their preferences, I recommend fast growing plants such as java fern and hornwort. Other plants that do well in a siamese algae eater tank include Anubias, Amazon sword plants, anacharis, and bolbitis.

How to decorate my tank?

Despite being constantly active you should provide ample swim in hide outs for your algae eater to rest or play in. Some recommendations include hollowed out logs, PVC pipes, tunnels, or commercially available tank decor. Just make sure that any decor you purchase has no sharp edges that could be a potential injury hazard.

Diet and Health

Fish Food
Different Types of Fish Food in a Container

While they are fairly low maintenance fish the siamese algae eater does have some particular requirements when it comes to their diet and health since they eat a high fiber diet.

What to feed siamese algae eater?

A majority of this fish’s diet consists of algae and plant matter. However, they have been known to eat dead insects or dead fish that they come across in their scavenging. A proper diet includes supplementing their scavenging with fish food, frozen foods, algae wafers, and fresh vegetables.

If this is the first fish you’ve fed fresh vegetables to, here are a few tips to get you started.

  • Veggies should be fully washed and checked for any bugs and worms
  • Greens such as spinach and lettuce should be blanched
  • Stems, skins, and shells should always be removed.
  • Tear/cut veggies into small, bite size pieces

One of my favorite commercial fish foods to feed algae eaters is spirulina pellets. These provide lots of vitamins and nutrition to help maintain health. However, you should be careful feeding your fish commercial food, if given too often they’ll stop eating the algae in your tank in favor of the better tasting commercial algae wafers.

…give your fish some live foods to eat to help bolster protein intake.

Occasionally you should give your fish some live foods to eat to help bolster protein intake. Examples can include brine shrimp, insect larvae, or bloodworms. While siamese algae eaters will eat any dead fish that happen to be in your tank, I extremely discourage using this as a source of protein as they could be infected with diseases.

When to feed siamese algae eaters?

You should only feed siamese algae eaters once per day. If given the chance they’ll eat as much as you allow them, however feeding them more than once daily will prevent them from being hungry enough to clean your aquarium of algae.

How much to feed siamese algae eaters?

When feeding this species use the three minute rule. In other words, only let them eat as much as they can in a three minute time period. Other animals in your aquarium might need to be fed more often than this but try to keep these bottom dwellers from receiving too much extra food as it is easy to accidentally overfeed them leading to constipation and bloatedness.

All leftover food should be removed from the tank immediately following the end of feeding time to prevent the fouling of your tank.

Siamese algae eater lifespan

In ideal aquarium conditions these fish can live up to 10 years. It is important to note that outside captivity the siamese algae eater doesn’t live quite as long.

Common diseases of siamese algae eaters? 

Siamese Algae Eater Searching For Food
(1) Siamese Algae Eater Searching For Food

These aquarium fish are relatively hardy and low maintenance, however they are very liable to experiencing constipation or bloating. However, since this fish doesn’t have a swim bladder like other fish you don’t need to worry about bladder infections.


Symptoms of constipation include stringy feces, lethargy, and disinterest in food. If your siamese algae eater shows signs of constipation it is likely that they have too much protein in their diet and you need to increase the fresh vegetable and algae availability. One of my go to fixes for constipation is adding shelled peas to their diet and allowing the high fiber content to do its work.


Fish suspected to be bloated should be placed in a separate tank with the water level just above their head and water changes every 2 days. Often caused by overfeeding, bloating can also be a sign of dropsy. Bloating caused by constipation should be treated by reducing the amount of food given. If nothing else works try placing your fish in a treatment tank with epsom salt which should help reduce some of the swelling.


The dreaded white spot disease symptoms include having white spots all over the body and fins and the fish rubbing against decorations. Ich is caused by a protozoan parasite and can be treated with aquarium salts or medicine like malachite green or copper sulfate.

Fin/tail rot

This disease is frequently caused by poor tank conditions. If you notice: your fish’s tail or fins look tattered; the edges of their fins have changed color; or there is inflammation around their fins, they may have fin/tail rot. Consider treating with an antibiotic, and keep a close eye on your pet. In rare cases, fin rot has been known to cause fish to lose the entire fin.


Fin/tail rot can also occur when a fish is injured due to nipping and the injury becomes infected. It is especially important to keep pristine water conditions in your aquarium when there is a fish with an injury.

Ways to prevent diseases

Maintaining a pristine aquarium environment and feeding a high quality diet is the easiest way to prevent diseases. You should always quarantine other fish and plants that you are adding to your community aquarium before placement to be sure you’re not transferring any diseases. Equipment should be well washed if used for more than one community tank to prevent bacteria transfer.


Make sure your aquarium is warm enough for your fish. Having a tank with a colder temperature outside the SAE’s range can lead to a compromised immune system.

Do Siamese algae eaters need oxygen?

All fish need oxygen and receive it in a form called dissolved oxygen (DO). Both plants and fish use DO in the aquarium which is why it is important to provide constantly circulating water. Circulation is especially important for bottom dwellers such as siamese algae eaters because the least amount of oxygen reaches the bottom of the tank.

In their natural habitat siamese algae eaters have an environment that is rich in oxygen due to the fast flowing water. Aquarium environments should replicate these conditions.


A Pair of Siamese Algae Eaters
(2) A Pair of Siamese Algae Eaters

Breeding these fish in captivity is almost impossible and is not recommended.

Can you breed a siamese algae eater?

It is almost impossible to breed a siamese algae eater in a home aquarium, and most fish that you see in the aquarium trade are bred in a controlled fish farm setting or caught in the wild.

How to breed a siamese algae eater?

There is not much knowledge on how to breed these fish in captivity because it really hasn’t been done except for on large, commercial fish farms. To induce breeding in captivity it takes artificial hormone injections which are not readily available for the home aquarium.

Want to know their courtship behavior? Watch this video below.

Siamese Algae Eaters’ Territorial/Courtship Behavior

What do siamese algae eater eggs look like?

As there are not many fish keepers or controlled fish farms who have successfully bred siamese algae eaters, there is not much information on what their eggs look like.

Is the siamese algae eater for you?

If you’re looking for another addition to your tank cleanup crew that is peaceful and will eat just about any kind of algae then the siamese algae eater is definitely for you!


In conclusion, siamese algae eaters are an important asset to any aquarist that is struggling with algae in their tank. With their easy care guidelines established above, and diverse diet they are a worthy investment to help keep your tank clean.

(1) aleander2137, CC BY-SA 4.0, via Wikimedia Commons
(2) Chiroptera man, CC BY-SA 3.0, via Wikimedia Commons

You May Also Like