Siamese Algae Eater Complete Care Guide: Is This Fish Right For Your Tank? is supported by our readers. When you buy through links on our site, we may earn a commission.

Both beginners and veterans of the fish keeping world can attest to how much of pain algae can be in your tank.

It’ll cover the walls, the floor, and it’d cover the ceiling too if it could! It’s can become exhausting keeping up with the number of algae and debris that your tank produces from housing several species of fish.

This can severely damage plants and the health of other fish if left unchecked.

That’s why bottom feeders and algae eaters have become an increasingly popular addition to tanks across the world.

This is where the Siamese Algae Eater comes in. They’re a unique fish and incredibly popular for their abilities to efficiently clean most of the algae within a tank.

On top of saving you time from cleaning the tank, you’ll save a bit of money by not having to buy it food. Your tank will adequately feed them and provide all the nutrients it needs.

The Siamese Algae Eater, or the Crossocheilus oblongus, is a wonderful addition to tank;, especially for beginners.

They’re a freshwater fish that hails from the carp family, Cyprinidae and are known to be extremely friendly and sociable with other fish in community tanks.

They’re ideal in large groups but will do well when kept by themselves as well. No matter how few or many fish are in your tank, the Siamese Algae Eater fits right in without an issue.

Their native habitat lies in Southeast Asian, mainly in the countries of Malaysia and Thailand. However, they’ve come a long way from their homes. Nowadays, breeders all over the world bring in millions of new Siamese Algae Eaters to be shipped all over the world.

They’re so popular because of their ability to defeat algae more so than any other species. They’re one of the best algae eaters available. That skillset coupled with their relatively easy care guidelines makes this one of the best species for beginner and veteran fish keepers to show off in their tank.

Another unique benefit of the Siamese Algae Eater is that they’re incredibly social and active. They’ll be bouncing off the walls and keep your tank lively and full of excitement. This also means that your Algae Eater will cover more ground and thus eat more algae in the process. It’s a win-win scenario.

Like most other algae eaters, they produce a large amount of waste. This is why a medium-sized tank of at least 20 gallons is recommended to house these fish. You’ll run into this problem with almost all algae eaters that can live in your tank so be prepared if that’s something you’re wanting to incorporate.

Be careful of having too many of this fish in your arsenal, you may find yourself having to clean their waste instead of them removing it for you.

Behavioral Notes

Siamese Algae Eaters are social, especially when you have them paired with others of their species.

They like to form groups and feed along the bottom of your tank together in a group. This group feeding can be interesting to watch. This coupled with the fact that they’re an active species means you may have a couple of bullets whizzing around in your tank.

They aren’t an aggressive species but other fish may mistake them to be. This is because of how quickly they move. They may bounce off of other fish or invaded their spaces. If you have other fish that are territorial or known to have a short fuse, it could cause issues.

However, the Siamese Algae Eater doesn’t mean it. They’re generally incredibly kind and friendly with other species. There are some instances where it has been noted that the Siamese Algae Eater is capable of being an aggressive fish. But, those instances are few and far between.

If you do happen to notice that they become aggressive, immediately remove them from the situation. They aren’t well-equipped to be fighting other fish and may become seriously hurt. Hopefully, you won’t run into this issue.

If you want the best community tank possible, pair them with other friendly species and let them loose. You’ll soon find you’ll have one of the liveliest tanks possible with activity always happening.

Siamese Algae Eater Appearance & Size

Being from the carp family, the Siamese Algae Eater looks extremely similar to other members of the family. The main difference is that they’re much smaller.

Their body is long and narrow and may reach up to a meager six inches. The small size and stature of this fish mean they’re great to have in small groups, even in small to moderately-sized tanks.

They have scales that line their body from head to tail. These scales are hard and will flake off but form the bulk of the protection for the Siamese Algae Eater.

Their colors may include:

  • Pale grey
  • Gold
  • Black stripes

A typical Siamese Algae Eater may have a gold coloring to their scales with a long stripe that runs horizontally across the fish.

If you find a stripe on your Algae Eater, you can use this as an indicator of their health. Sometimes the stripe may fade in color. This can indicate a variety of issues including stress or feeling threatened by a predator.

They can fade their colors to increase their ability to blend in with the background and hide from aggressive fish. It’s their camouflage.

On the flip side, a faded strip may also indicate that it’s mating season. If you notice that your Siamese Algae Eater begins to go through a mating process, don’t be surprised when the stripe fades.

The Difference Between Male and Female

For almost half of the Siamese Algae Eater’s life, there is largely no difference between male and female fish.

The only giveaway between the two will be their size. After approximately four years, the females will begin to get larger than the males. The females may reach a size of up to 30 percent bigger than a male fish.

Siamese Algae Eater VS Flying Fox

It’s been a conundrum since the beginning of fish keeping.

The Siamese Algae Eater and Flying Fox look almost identical but are vastly different species of fish. They’ve been confusing amateurs and experts alike for years.

If you’re looking at the two side by side, you’ll notice that they both have similarly colored scales and a black stripe that runs along the side of its body. If you’re not well-versed in the differences, you can be easily fooled like many others are.

The easiest way to see a difference is by inspecting the black line that runs along the side of the fish. A flying fox’s stripe will typically appear smoother and will end where the tail fin begins.

The Siamese Algae Eater’s stripe is similar, but not the same. Their black stripe will continue until it reaches the end of the tail find, not the beginning.

If you can closely inspect both fish, there is an even easier option. However, it’ll be difficult to see if your fish are flying every which way within your tank.

If you can, check the corner of the mouth for a flap. If you find one, you’ll know it’s a Flying Fox rather than the Siamese Algae Eater. In the same vein, if you don’t find a flap, you can safely conclude it’s a Siamese Algae Eater.

Habitat and Tank Conditions

Like with any species of fish, you’ll want to imitate the natural environment of your fish as best as possible.

Because of their origins in Southeast Asia, their habitat will imitate their family member, the Asian Carp, closely.

These types of habitat have several things in common that you should aim for:

  • Slow current
  • Slightly acidic water
  • Lots of structure such as driftwood, rocks, sand, and caves
  • A ton of plants or vegetation

They require these structures because they’re a bit of a shy fish. Their time is spent either feeding or in the structure that they’ve deemed their home. They rarely will venture to the top of the water column and generally stay toward the bottom where their food supply is at.

Try having several pieces of wood and shaded areas that can provide the fish with a sense of protection. This will keep them happy and comfortable

Regarding the conditions of your tank, you’ll want a soft, sandy bottom ideally. Because they live near the bottom and feed on the bottom, they can be easily scraped if there are sharp objects strewn about your tank. However, their scales will adequately protect them from gravel and other similar surfaces so don’t fret too much.

While the Siamese Algae Eater is an herbivore, it shouldn’t be targeting any of your plants. They’ll typically stick to algae that naturally grow along the bottom of the tank or on top of surfaces and structures. If you notice that they are beginning to feed on your plants, it’s a sign that they’re being underfed or not receiving enough nutrients from the algae that are being naturally produced.

Keep your Algae Eaters well fed to avoid your plants being nibbled on.

Recommended Tank Mates for the Siamese Algae Eater

The Siamese Algae Eater is a friendly fish that you won’t typically have to worry about being aggressive.

However, because they live on the bottom, you should be aware that other bottom feeders tend to be aggressive. Make sure you’re avoiding species that have this problem.

Avoid other aggressive fish that are known to attack other fish such as bettas and cichlids.

Danios, guppies, and other smaller, non-aggressive fish are the best candidates to keep your Siamese Algae Eater company throughout their days.

Food & Diet

For the most part, you won’t have to spend too much time feeding your Siamese Algae Eater.

The reason can be found in their names. Normally, they’ll be kept happy by the algae that are being naturally produced in your tank. However, if you find that your tank isn’t producing enough algae or other food, you can feed your Algae Eaters a variety of vegetables

This can include:

  • Peas
  • Carrots
  • Cabbage leaves
  • Other various nutritional vegetables

Be careful of overfeeding, Siamese Algae Eaters are known to be some of the hungriest fish you can find on the market. They’ll constantly be eating if given the opportunity.


Siamese Algae Eaters are notoriously difficult to breed outside of a breeding environment on a commercial farm.

The act of sex is difficult as well because females become increasingly larger as they get older.

Unfortunately, not a lot of information is known on how to reproduce breeding environments outside of a commercial environment.

Siamese Algae Eater Care

Siamese Algae Eaters are generally a fairly healthy fish. They aren’t known to get any strains of serious diseases, but that doesn’t mean they can’t become sick.

There are some easy steps you can perform to ensure that your fish is living in a healthy and adequate environment:

  • Keep the quality of your water high a consistently clean it
  • Be mindful of chemicals and toxins you may introduce into your tank through foreign objects or plastic materials
  • Don’t be stingy, give them high-quality food when feeding them substances other than algae

Are They Right for You?

The Siamese Algae Eater is perfect for a beginner and can prove incredibly useful an interesting to a veteran fish keeper as well. Regardless if you’re new to keeping fish or have been doing it for years, keeping a few of these fish in your tank is hardly ever a bad idea.

Because their easy to take care of and a generally friendly fish, you’ll be granted a lot of leniency regarding mistakes you may make.

In the end, you receive a cleaner tank and a friendly, beautiful fish to keep your tank lively and exciting.

There perfect or community tanks and make your life easier. It’s a combo you’ll rarely find.

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Jeff Colt

Jeff Colt

Hello, I'm Jeff- an aquarium enthusiast with over 25 years of experience caring for a wide array of tropical fish, including koi, goldfish bettas, cichlids and more! For me: Aquariums are like jello - there's always room for more!

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