siamese algae eater care guide header

One of the most annoying issues with any aquarium is algae growth. If you look outside my window at the pond in the space I share with my little community, you’d see the piles and piles of algae – making it a “scummy little pond” to quote my partner.

The pond is gorgeous – just as your aquarium is – but the algae just takes away from the beauty.

Algae isn’t all bad, but generally speaking, none of us want it in our fish tanks. That’s one way that these amazing little silvery fish come in handy – Siamese Algae Eaters.

Let’s take a look at a Siamese algae eater care guide so that they can thrive and help the rest of your aquarium life (such as Pea Puffers) thrive as well.

siamese algae eater on the bottom of a tank

Quick Intro to Siamese Algae Eaters

Scientific NameCrossocheilus oblongus or crossocheilus siamensis
Other NamesSAE
Care LevelEasy

Natural Habitat, Identification, and Where to Buy

Siamese Algae Eaters, as their name implies, naturally come from Asia, primarily found in regions near Chao Phraya and the Mekong basins of Thailand and Cambodia. They swim into flooded fields during the rainy season each year and live in water that has extremely low pH and almost zero water hardness.

They natively live in fast-moving water – streams and rivers – with sand, pebbles, and boulders as their natural substrate. The like living in tree roots and graze on green algae, diatoms, and microorganisms that live on the logs, stones, and other hard objects beneath the water’s surface.

These little guys use their sucker-like mouths to attach to smooth surfaces in their natural habitats – and your aquarium – and go with the high flow easily.

True Siamese Algae Eaters have long, narrow bodies that reach up to six-inches in length. They’re usually a pale gray or silver, with a lengthwise black stripe that runs from head to tail.

Many people confuse the True Siamese Algae Eater with other fish. Folks have issues telling Chinese algae eater vs Siamese algae eater apart, as well as Siamese algae eater vs flying fox.

They look very similar with long bodies with black stripes. The truest way to tell the species apart is that the Siamese Flying Fox has flaps in the corners of their mouths while True Siamese Algae Eaters do not.

The black stripe on the Flying Fox also tends to be smoother and ends where the tail fin begins. Since it’s hard to see the flap around the mouth while the fish are swimming, the stripe is the easier identifying mark for aquarists.

This video shows you some other easy ways identify True Siamese Algae Eaters from False Siamese Algae Eaters, along with a few interesting facts, like eating habits as they age, their looks, et cetera.

SAEs are pretty inexpensive and reasonably easy to obtain online. You’ll find Siamese algae eaters for sale at:

Optimal Water Conditions for Siamese Algae Eaters

Temperature 77 – 82°F
Water Flow Rate moderate to fast
pH 6.0 – 8.0
Hardness 5 – 20
Tannin Recommendations SAEs love driftwood, but their tankmates not do so well with the tannins typically found in it. Be sure to boil and scrub any driftwood thoroughly to avoid contaminating the environment.
Other Water Chemistry Needs It’s important to note that “algae eater” does not mean “garbage eater.” These fish do best with very clean, pristine, high-flowing water. They are not stagnant stream dwellers and need pure, clean water for their survival and health.

Tank Setup

Minimum Tank Size 20 gallons + 10 gallons per each additional SAE
Optimal Tank Size 30 gallons or larger
Optimal Tank Shape Long
Recommended Filter Type Canister filter
Extra Air Flow and How to Provide If you’re going for the biotope aquarium with fast-moving water, your best way to create air flow is through the use of directionally positioned powerheads, wavemakers, or water pumps that will create the more intense water flow rate.

SAEs are great for community tanks. But their preferred aquarium is going to be the biotope aquarium that resembles a fast-moving tropical stream. These tanks should be at least 20-gallons in size, but they’re best if at least 30-gallons in size and at least 36-inches in length.

Creating the Landscape

You’ll want to set up the tank with substrate combinations of pebbles and larger stones – resembling small boulders – and some driftwood, as the algae eaters love to live in roots and wood. This will help them find safe places to explore and live without threat from other fish.

SAEs also do best with live plants. They look great – sure – but they also provide the best feeding stations for your little algae eaters. The surface of the aquarium plants provide you algae eaters with bacteria, zooplankton, worms, and other organisms that keep them healthy and happy.

They do love algae eating, but all of these other foods are equally important to their thriving.

If you’re really not feeling the fast stream aquarium, however, you can go with something calmer with large-leafed plants like Amazon sword plants.

The algae eaters can still happily live here and nosh on the critters living on these plants.We’d also like to note that it’s important to keep a tightly fitting lid on your aquarium where the SAEs live. They’re jumpers and may escape without the properly fitted lid.

Best Plants Bolbitis, Anubias, Amazon swords, hornwort, anacharis, Java fern
Best Lighting Low
Best Decorations Driftwood, live plants, hiding structures such a caves and large rocks, soft and smooth substrate
Decorations to Avoid Sharp gravel and rocks
golden siamese algae eater fish
Golden Siamese Algae Eater

Physiological Considerations

Maximum Siamese Algae Eater Size 6-inches
Rate of Growth SAEs mature to full-size anywhere between six months and two years, depending on circumstances like water temperature and food supply
Siamese algae eater lifespan 10 years
Temperament Peaceful
Preferred Tank Region Changes with age
Gill Considerations Siamese Algae Eaters naturally live in fast moving water. This type of environment in your aquarium is best for the health of their gills – keeping them disease free.
Swimbladder Considerations True SAEs do not have swim bladders. This means they are nearly in constant motion in order to avoid sinking and to maintain buoyancy.
Fin Shape Considerations They rely on their fins to hold them aloft while resting. Extra care must be taken for their fins. Be sure to avoid any sharp objects in the aquarium for this reason in particular.


Siamese Algae Eaters are pretty chill fish. They rarely pick fights with others, since they’re not particularly territorial, and get along well with pretty much any critter you have. They do, however, nip at the fins of long-finned fish – like bettas, guppies, platys, or swordtails, for example – so avoid homing these fish together.

That being said, an algae eater with betta fish can be a reasonable pairing if the community tank is large enough to give both fish their space. You just need to keep an eye on the bettas fins for a while to make sure there’s no nipping going on.

Siamese Algae Eaters do best in a school of four to six SAEs, but they can survive alone. They do well in larger schools, as well, assuming you provide them with a sufficiently large environment. That means 20 gallons for your first SAE, with an additional 10 gallons per SAE after that.

Potentially great Siamese algae eater tank mates include:

Because these fish are non-aggressive, it’s also advisable that you don’t pair them with overly aggressive fish, as they will have difficulty defending themselves and will have much higher stress levels, which can cause severe illness or even death over time.

If you house other bottom-dwellers with these fish – once they’ve grown, this is where they chill most often – choose non-territorial fish for tankmates as other bottom dwellers tend to be extra territorial due to their scavenging nature.

Corydoras are a great pairing if you’re looking for other bottom dweller fish to live with your SAEs.

You should specifically avoid red tailed sharks and cichlids for housing with your SAEs, as they are extremely territorial and aggressive and will cause issues for your SAEs.

The exception can be Angelfish, though this pairing may cause issues for the Angelfish due to its long, glorious fins. If the tank is large enough, and you love Angels, you can house them together on a trial basis to see if the SAE goes after the Angels’ fins or not. In large tanks, the Angel may well do just fine.

Gender, Breeding, and Reproductive Considerations

Until SAE fish are between three and four years old, its very difficult to sex them. In fact, its not until this time that there’s really any visible cues. Female Siamese algae eater full grown are about 30% larger than the males – and that’s your best clue for knowing which gender you’ve got.

It’s challenging – and very unlikely – to breed SAE fish at home. Most of the aquarists and experts have been unsuccessful in breeding the fish outside of a fish farm setting.

They do appear to breed as other fish species, however. The assumption is that the added hormones used in a fish farm environment is how the fish breed successfully there and not at home.

Nutritional Needs

siamese algae eater along the bottom of a green tank

The SAE is an omnivore in the wild. They eat algae, periphyton and phytoplankton. They’ll eat just about any commercia fish food in the aquarium, as well, including live fish food, meaty foods, algae wafers, catfish pellets, or processed fish food.

Note: We never recommend feeding flakes or pellets, or any other foods that are high in grains and unnatural ingredients such as dyes and artificial flavors.

In the wild, the Siamese Algae Eaters feed on algae, periphyton and phytoplankton. Will take any commercially available fish food, live food, meaty foods, algae wafers and catfish pellets. Will eat green hair algae. May ignore algae in favor to commercial food if given a diet too rich in protein.

So, what to feed algae eaters? A combination of the following food types will be a great way to maintain and keep your algae eaters health up.

Best Sustenance Food Type Sinking algae wafers, both as treats and as a semi-regular food source – probably twice weekly for good measure. High-quality, sinking pellets (low starch content) and sinking flakes (low starch content), live or frozen brine shrimp, and live or frozen bloodworms
Additional Food for Optimal Health Tubiflex, freeze-dried bloodworms, vegetable-based foods
Special Foods and Considerations for Best Color and Growth There aren’t any specific special food considerations for these guys. They thrive on all of the foods mentioned and don’t particularly develop brighter colors, save around spawning or stressful situations, when they actually fade their color instead.
When and How Often to Feed Fish Based on Life Cycle They should be fed once per day – and only enough that they can eat in about two to three minutes’ time. Even if your other fish need to be fed more often than this, do what you can to limit their feeding window to this small, single time per day.

Siamese Algae Eaters are a bit like teenagers – they would eat all day long, if they are permitted. So it’s a hard balance between under and overfeeding your SAEs.

They eat the plants in the aquarium. They eat any bacteria and microorganisms growing in there. They eat algae, as their name suggests. And if you feed your SAE fish too much fish food, they will stop eating the algae in favor of the more flavorful algae wafers and bloodworms.

A specific feeding schedule will help with issues of over or underfeeding as well.

Common Diseases and How to Avoid and Treat Them

Thankfully, Siamese Algae Eaters are prone to very few diseases. They can, of course, be susceptible to some of the more common issues that affect other freshwater fish tank species, however. But these do give clear signs and can usually be treated quickly and reasonably easily.

Ich is one of the more common diseases in freshwater aquariums. A tiny parasite causes the disease, which can be identified by small white dots on the body of the infected fish.

Often this is preceded by your fish rubbing its body against a rock or other scratchy surface in an attempt to scratch that itch. This disease is most easily prevented by regular water changes.

Best Antibiotics: Generally speaking, prevention through regular water changes is your best bet. And if your SAE does contract the Ich, its best treated through regular water changes and higher-quality foods, if you’ve gone with anything less than top-notch in the past.

Recommendations for Sick SAEs: Be sure to make sure the Siamese algae eater temperature is warm enough for your fish if they are ill. They do best in warmer water, which means your fish may well do better and become healthy again simply by a mild and gradual temperature increase until the ideal temperature is reached.

Hospital Tank or Isolation Within the Community Tank Specifics: Thoroughly scrub and sanitize any decorations that you may have in the tank. Do not add anything new to environment while SAEs are under medical treatment.

3 More Things to Know About Siamese Algae Eaters

Just for fun – and a little more knowledge – here are three facts about Siamese Algae Eaters that you probably don’t already know.

  1. Siamese Algae Eaters are closely related to carp.
  2. True Siamese Algae Eaters are far from the most common choice you’ll find in stores. In fact, most often when you do find them there, they’re not actually True SAEs. Be sure to check that stripe to verify you won’t be needing a Siamese Flying Fox care guide instead.
  3. SAE fish are arguably the absolute best algae cleaner for any aquarium.

About The Author

3 thoughts on “How To Care For Siamese Algae Eater Fish: A Complete Fact Sheet, Breeding, Behavior, and Care Guide”

  1. Hi Matt,
    We have introduced 4 very small (2.5cm at most) Siamese algae eaters to our 160L tank in the last 3 weeks. We just noticed a tiny baby one has appeared today. My question is do they give birth to live young or eggs? There is actually not much information on their young as from my quick search it says it’s rare that they give birth in tank conditions. We have the temperature set at 24° in a 160L tank. I hope the baby survives we have 5 Platy fish and 2 Goldfish I’m worried it might inadvertently get eaten. Or I might accidentally collect it when I’m cleaning the gravel.
    Kind regards,

  2. Terry Bregazzi

    Hi Matt,
    I have 4 SAEs and all doing well,untill now.
    They are about 4 years old now and recently one of them has developed a rather fat belly.
    I note that breading in a tank is not really heard of but it would look just like one is very very pregnant.
    I’m worried that it not pregnant and that this is some type of growth.
    Can you help with any suggestions please as to what this could be.
    Kind regards

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