If you’re searching for a freshwater fish that will help knock down the amount of algae in your tank, look no further than the Siamese algae eater.

These fish have been used as a go-to option for freshwater aquarists of various experience levels for years, and that’s not going to stop anytime soon.

Here’s why:

They’re fun and social community fish that can get along with pretty much any other species you have in your tank.

They are also low maintenance and don’t require an extensive amount of care to thrive. This is a major draw for a lot of tank owners.

We also think that they’re pretty fish! Sure, they won’t knock your socks off with color like an African cichlid, but we think they have a certain understated beauty to them.

But when it comes down to it, they have a reputation for one specific thing:

Scarfing down algae.

This combination has made them a very popular fish, which is why they were one of the first fish we wanted to write a care guide for!

In this guide, you’ll learn everything you need to know about Siamese algae eaters. Understanding how to take care of them will help them thrive, and allow them to them contribute to the rest of your tank as well.

Species overview

Siamese algae eaters (Crossocheilus siamensis or crossocheilus oblongus) are freshwater dwellers that are members of the carp family of fish species termed Cyprinidae.

Siamese algae eater overview

This tropical fish species is naturally found in the mainland of Southeast Asia in places like Thailand, and are bottom dwellers. They can be found in the Malay Peninsula and in the basins of Mekong and Chao Phraya.

Siamese algae eaters prefer their natural habitat living environments of rivers and streams. They can also often be found in flooded forest regions during this geographical region’s rainy season.

Benefits of adding them to your tank

As their descriptive name implies, Siamese algae eaters (or “sae” for short) feed on naturally growing algae found in their native habitats. For just this reason alone, these peaceful fish are terrific for keeping fast-growing algae from taking over an aquarium space over time (they’re a lot like Amano shrimp in this way).

While many fish experts recommend a little algae growth to maintain the proper food and ecosystem balance inside your tank, too much of it can be detrimental to the fish and other water creatures living there.

Adding Siamese algae eaters to an aquarium helps to control algae growth and maintain good aquarium health that is essential for the well-being of each occupant living inside of the tank.

What do they look like?

Siamese algae eaters are slender and long fish that are brownish-beige in color. This fish species is identifiable by a bold black stripe that runs over the entire length of the body, nose to tail, with one eye-catching stripe line on each side.

Siamese algae eater swimming toward the surface of the water

This stripe tends to fade against water background features that help the fish to be camouflaged, or hidden, from its natural predators in the wild.

The telltale black stripe runs to the tip of the fish’s almost perfectly clear caudal fin with a mustache that some call Rostral barbels.

Side-by-side, the female Siamese algae eater has a somewhat broader expanse of their middle section when compared to the slim and sleeker male fish.

One other appearance detail is that these fish do not have the usual “swim bladder” common in most fish. If these fish do not stay in constant motion, they will quickly sink down to the bottom of a tank or other water habitat.

Siamese algae eater size

Siamese algae eaters can get a bit larger than most freshwater tropical fish species that you’ll find in various tanks. These bottom loving fish can grow up to approximately 6 inches (16 cm) and sometimes even a bit longer.

Fish owners should plan to have a tank that is at least 30 gallons in size for best overall results when caring for this fish. This will give them room to swim comfortably and find places to hide when they need space.

Siamese algae eaters vs Siamese flying fox fish: how to tell the difference

It can be difficult to tell if a fish being purchased for an aquarium is actually a Siamese algae eater or if it’s a flying fox instead. The flying fox looks very similar, but fish owners can look for a few differences to ensure that they’re getting the right fish.

The flying fox tends to have a light golden band that can be seen along the top border of the telltale black stripe situated on sides. A true Siamese algae eater doesn’t have this more distinctive gold border, although Siamese may have a faded gold tinge in certain lights. Another distinguishing difference is that the flying fox will have an orange-yellow tinge to its fins, and the Siamese’s fins are always clear.

Proper Siamese algae eater care

Before committing to caring for Siamese algae eaters, it is essential to learn how to keep them healthy and what diseases you should be mindful of.

In general, these fish are wonderful choices for beginning aquarium enthusiasts as they require little care and are not particularly picky about their tank mates, food and other living situations.

One word of caution is to not overpopulate the tank with too many Siamese. Even though these fish are amazing for their constant tank cleaning action when feasting on algae, it’s important to remember that any fish, including the Siamese variety, will create body waste of its own that can dirty up the tank.

Below we get into the nitty-gritty details about additional tank conditions that Siamese fish need to remain healthy and happy. This includes warmer water temperatures, slower-moving currents and plenty of cool shady areas near the bottom of the aquarium.

With the proper diet and care, the lifespan of Siamese algae eaters can be up to 10 years.

Food & diet information

Like most fish species, aquarium owners should feed each species the correct food to maintain health and extend their lifetime. Siamese algae eaters tend to be less picky about the available food and are omnivores. This means they will eat and scavenge dead insects, plant matter, and dead fish (among other things). 

Diet in the wild

In their native environments, the Siamese algae eaters feed on various algae forms, phytoplankton and periphyton. They’ll also munch on dead fish and insects if they come across them.

Diet in your aquarium

For best results when caring for Siamese algae eaters you’ll want to recreate their natural freshwater environment as much as possible. This fish likes various tropical algae that fortunately will grow inside an aquarium (since it should be mimicking a tropical environment).

Most fish experts recommend that these Siamese algae eaters also be fed a diet mixture of fish food that includes some protein and natural plant-based foods. In the tank, these fish can be fed pretty much any commercial or live foods.

A caution for feeding these fish is to not under or overfeed them. When underfed, the Siamese tend to nibble on other plants inside the tank that you might not want them to.

On the other hand, too much protein can cause the fish to be less inclined to feed on its preferred algae menu. This could make the tank harder to keep clean since they’ll have spoiled their appetite!

Ideal tank size & water conditions

The Siamese algae eater is relatively easy to care for, and it doesn’t require a lot of fuss or fancy tank conditions in order to thrive.

Generally, plan to go with a minimum tank size of 25 to 30 gallons of water. This will allow them to be active and explore, while also having places to hide.

Keep the water pH level at 6.5 to 7.0 which replicates the slightly acidic and constant water conditions these fish encounter in their normal dwelling places in the wild.

Since Siamese are a tropical fish that lives in freshwater streams and rivers with lower current action, keep the aquarium water temperature set at 75°F to 79°F for best results.

The ideal water hardness range is between 5 and 20 dH.

Other tank and habitat tips

It’s important for the tank to include live plants like those found in this fish species’ natural habitat. A tip is to use fast-growing plants just in case your fish get hungry for a snack and chow on the live plants. If they do, the plant can handle it and will soon be back to its previous size and height.

Sandy bottom material is also ideal for keeping this bottom loving fish safe from scratchy rocks or reefs when resting.

Remember to provide enough shade and hiding spots to keep stress and swimming fatigue levels lowered too. Small tunnels, swim-in hide-outs, and hollowed-out logs all make perfect tank additions for these fish.

Keep a lid over the aquarium to keep these more active fish from jumping out when cleaning the tank or during feeding times.

Behavior and temperament

The Siamese algae eater is known for its tranquil and peaceful temperament. This characteristic makes these fish an excellent choice for community aquariums that have various types of fish inside.

Swimming Siamese being active

These always moving fish are considered social, and they get along well with many other fish and water creatures typically found in warmer freshwater environments.

There are a few cautions that first-time owners should be aware of before introducing this fish to your aquarium. Since the Siamese must remain in motion due to the absence of a swimmer bladder, these algae eaters need places to hide at the bottom of the tank when they need rest or desire to be alone.

Fish owners can create an ideal habitat for Siamese algae eaters by providing some cave-holes and various plants or objects like driftwood at the bottom of the aquarium. This gives these active fish somewhere to get away from the others when needing a spot to rest and unwind from their busy lifestyles.

The behavior of Siamese algae eaters can be described as active and definitely social. These fish are always on the go, and they’re always looking for algae and other plankton usually found on tank bottoms and walls. Due to their active nature, Siamese algae eaters make interesting fish to watch as opposed to their less active counterparts.

Aquarium owners should understand that while these fish are not prone to aggression towards other fish, they can be a stress for those other aquarium dwellers due to their constant motion throughout the tank. This action might stir up another fish’s quiet area. Adding enough hiding places helps prevent this problem if you have a community tank.

If a Siamese algae eater does appear aggressive, you should carefully monitor the situation and determine which fish or other creature is causing this normally docile fish to react in this manner. In rare cases, the fish might have to be kept in a separate tank.

These fish can be somewhat territorial in nature towards their own kind, and it is best to keep a single Siamese or keep 5 or more in a group. This replicates their normal situation in the wild and will prevent a single fish from “claiming” an area of the tank.

Siamese algae eater tank mates

Typically, Siamese algae eaters are bottom-dwelling fish that get along well with a wide variety of tank mates. However, choose other bottom-dwelling fish mates carefully, as the vast majority of bottom dwellers are a bit territorial in their normal nature.

Their peaceful nature makes them good companions for a whole wealth of freshwater creatures (big and small). Considering fish from the Corydoras family is a tried and true pairing if you’re looking for a specific species to match them with.

Avoid Cichlids and red tailed sharks as they are more prone to being territorial and aggressive. A possible exception to this rule is the Angelfish.

Some recommended tank mates include:

  • Guppies
  • Tetras
  • Danios
  • Barbs
  • Any docile gouramis

Breeding

It can be difficult to breed Siamese algae eaters in a normal aquarium setting. Fish experts simply do not know as much about successfully breeding this species when not in a controlled fish farm setting.

They do appear to breed like most other fish of their type, but most fish owners end up relying on fish farms for expanding their numbers of Siamese algae eaters. Additionally, these fish require added hormones even when breeding in a fish farm environment.

If you’re thinking about breeding Siamese algae eaters on your own, don’t get your hopes up. You’re better off keeping them happy and healthy if you plan on keeping them in your tank.

Conclusion

As you can see, these fish make a fantastic and fun addition to pretty much any freshwater tank and can get by without a lot of attention.

Simply take care of their basic needs, and they’ll return the favor by taking care of algae in your tank!

We hope that you now have a better understanding of Siamese algae eaters as a species and how to help them thrive. If you have any feedback or questions regarding this fish you can always get in touch with us and let us know!

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