Siamese Algae Eater
Crossocheilus oblongus
Also known as SAE, Siamese Flying Fox, Crossocheilus langei
Edited by Ivan F. · Reviewed
Beginner verdict
A slim, black-striped fish famous for eating stubborn black brush algae, though it grows far larger than most beginners expect. It needs a large, long tank and a group, because singles turn skittish and weaker fish get bullied. Many similar fish are sold under this name.
Care at a glance
- Min tank size
- 80 US gal
- Footprint
- 59 x 18 in
- Temperature
- 68–79 °F
- pH
- 6–7.5
- Hardness
- 1–15 dGH
- Swim zone
- Bottom
- Min group
- 6 or more
- Lifespan
- 5–10 years
Siamese Algae Eater tank mates and swim zone
Bottom
Spends most of its time in this part of the tank.
Trigonostigma heteromorpha
Danio rerio
Puntius titteya
Barbodes semifasciolatus
Poecilia reticulata
Xiphophorus maculatus
Paracheirodon innesi
Siamese Algae Eater is much larger than Neon Tetra and may frighten or even eat it.
Paracheirodon axelrodi
Siamese Algae Eater is much larger than Cardinal Tetra and may frighten or even eat it.
Hyphessobrycon amandae
Siamese Algae Eater is much larger than Ember Tetra and may frighten or even eat it.
Hyphessobrycon herbertaxelrodi
Siamese Algae Eater is much larger than Black Neon Tetra and may frighten or even eat it.
Mikrogeophagus ramirezi
Their temperature ranges do not overlap, so one of them would always be stressed.
Melanotaenia boesemani
Their temperature ranges do not overlap, so one of them would always be stressed.
Carassius auratus
Goldfish suit cooler water and are not suited to tropical tanks, so Siamese Algae Eater is a poor match.
Siamese Algae Eater feeding and care
How to feed
- Let it graze algae, but do not rely on algae alone.
- Add sinking wafers, pellets and blanched vegetables.
- Feed small portions you can see finished within a couple of minutes, because overfeeding fouls the water fast.
Telling males from females
Sexually mature females are thicker in the body than males. Young fish cannot be reliably sexed.
Siamese Algae Eater care mistakes to avoid
- Do not buy just one or two. Keep at least 6 fish so they feel secure.
- Plan for a very large tank. Tiny juveniles grow into big, fast adults.
- Buy carefully. Lookalikes such as flying foxes get far more aggressive.
- Use a tight lid, because this active fish can jump when startled.
- Check your tank before you buy. Our sourced minimum is 80 US gallons.
Siamese Algae Eater tank setup
For bigger species and larger schools. Check your stand and floor can carry the weight.
TankAt least 80 US gal (304 L), 150 x 45 cm
The smallest tank our sources give for Siamese Algae Eater. We list only tanks that hold this volume (allowing 10%, so a standard size counts) and have at least this much floor.
None of the tanks we recommend is big enough for this species yet. See Best 40-Gallon Breeder Tank (or a 55) for what to look for.
Starter kitA kit with the tank, filter and light in one box
We list only kits whose tank fits Siamese Algae Eater, up to twice its minimum volume. A kit whose heater has a fixed setting shows only when that setting is inside Siamese Algae Eater's temperature range.
None of the kits we recommend fits Siamese Algae Eater yet. See Best Aquarium Starter Kit: What to Look For for what to look for.
FilterLarge hang-on-back or canister filter
Handles the extra waste. Canisters also hold more media and run quietly.
Seachem Tidal 75 Power Filter US
Marineland Penguin PRO 275 Power Filter US
Tetra EX 700 Plus External Filter Spain
Seachem Tidal 75 Power Filter Spain
Why we chose these (Best Filter for a 40 to 55-Gallon Tank). Nobody here has used or tested them.
HeaterKeep it at 68–79 °F (20–26 °C)
Adjustable heater, about 5 W per gallon: 200 W at 40 gallons, about 275 W at 55. Enough power for a large volume. Two smaller heaters that add up to that figure add a safety margin.
Aqueon Pro Adjustable Heater 200 W US
Aqueon Pro Adjustable Heater 300 W US
Tetra HT 200 Electronic Heater Spain
Eheim Thermocontrol e 150 Heater Spain
Why we chose these (Best Heater for a 40 to 55-Gallon Tank). Nobody here has used or tested them.
Water conditionerDechlorinator such as Seachem Prime
Tap water contains chlorine or chloramine that harms fish.
Seachem Prime US
Fritz Complete Water Conditioner US
API Betta Water Conditioner US
sera aquatan Spain
Tetra AquaSafe Spain
Sold at Kiwoko · Sold at Tiendanimal · Sold at zooplus.es · Maker's details
Why we chose these (Best Water Conditioner for Betta Fish). Nobody here has used or tested them.
Test kitLiquid kit such as API Freshwater Master
Tracks ammonia, nitrite, nitrate and pH while the tank cycles.
API Freshwater Master Test Kit US
API General & Carbonate Hardness Test Kit US
See it at The Shrimp Farm (a retailer; affiliate link) · Sold at Bulk Reef Supply · Maker's details
sera aqua-test box (Cl) Spain
JBL PROAQUATEST COMBISET Plus NH4 Spain
Why we chose these (Best Test Kit for a Freshwater Aquarium). Nobody here has used or tested them.
SubstrateDoes well in most tanks; a stream-style setup with rocks and gravel suits it best.
We are still choosing products for this.
Hiding places and decorRoots, branches and boulders that form nooks and shaded spots suit it best.
We are still choosing products for this.
PlantsMostly safe with live plants
Cycle the tank before adding animals. See our guide on how to cycle a fish tank.
Where to buy Siamese Algae Eater
Stores that list it under the same scientific name as this page. Links marked as affiliate links may earn us a commission. We have not bought from them, so check each store's own terms.
See it at The Shrimp Farm (a retailer; affiliate link)
We have not found a store that sells Siamese Algae Eater under its scientific name yet. We add stores as we confirm them.
Live animals and plants travel by courier. Check the store's live-arrival guarantee, and only buy once your tank has cycled (see how to cycle a fish tank).
Some US states restrict certain species. Check our US state aquarium rules table and your state's own rules before you buy.
Siamese Algae Eater FAQ
What size tank do Siamese Algae Eaters need?
Our sourced minimum is 80 US gallons (304 liters), with a footprint of 150 x 45 cm. A bigger tank is always easier to keep stable.
How many Siamese Algae Eaters should I keep?
Keep at least 6 fish. Bigger groups usually look better and behave more confidently.
What can live with Siamese Algae Eaters?
Good matches on our list include Harlequin Rasbora, Zebra Danio and Cherry Barb. Avoid German Blue Ram and Boesemani Rainbowfish.
How long do Siamese Algae Eaters live?
Care guides report about 5–10 years. Stable water and a good diet make the biggest difference.
How can I spot a true Siamese algae eater?
A true SAE has a straight black stripe running into the tail and has no flaps on its mouth. Lookalikes often have a stripe that stops before the tail.
Siamese Algae Eater facts and sources
- Family
- Cyprinidae
- Native to
- Thailand and Malaysia
- Adult size
- 5.9 in (15 cm)
- Temperament
- Peaceful
- Social needs
- Schooling/Shoaling (6+)
- Diet
- Algae Grazer
- Water flow
- Moderate
- Substrate
- Any
- Live plants
- Mostly Safe
- Shrimp
- Adult Shrimp Only
- Fin nipping
- Low
- Vulnerable to nippers
- No
- Breeding
- Difficult in Home Tanks
Sources
- Seriously Fish: Tank size, water ranges and behavior
- FishBase: Cross-check of water ranges and size
Lifespans are approximate and come from aquarium care guides, because these databases rarely publish them.
Where sources differ, we show the Seriously Fish aquarium figures.
Spotted something wrong? Report a parameter correction. For a sick fish, see our veterinary disclaimer.