Siamese algae eater care
Crossocheilus oblongus · Chao Phraya and Mekong basins
Siamese algae eaters are among the few fish that eat black beard algae, mostly while young.
- Tank size
- 29 US gal or larger
- Temperature
- 72 to 80 °F (22 to 27 °C)
- Group size
- Alone or in a pair
- Temperament
- Peaceful
- Adult size
- 6 in
- pH
- 6.5 to 7.5
- Hardness (GH)
- 4 to 15 dGH
- Lifespan
- 8 to 10 years
- Diet
- Omnivore
- Care level
- Easy
In a 29 gallon
30¼ × 12½ × 18¾ in outsideHow to keep Siamese algae eaters
Siamese algae eaters are among the few fish that eat black beard algae, mostly while young. They grow to about 6 inches and need a 29 gallon or larger tank with a lid. Look for a black stripe that runs right through the tail; lookalikes such as the Chinese algae eater turn aggressive.
Diet: Omnivore: algae including black beard algae when young, wafers, vegetables, pellets. Fish food types compared · how often to feed.
Where they swim: Bottom of the tank.
Siamese algae eater tank mates
Share the temperature and water, and neither side eats, nips or bullies the other. Check the full group in the stocking checker.
Angelfish
6 in · 29+ gal · 76–84 °F
Rosy barb
6 in · 29+ gal · 64–77 °F
Three-spot (blue) gourami
6 in · 29+ gal · 72–82 °F
Electric blue acara
6 in · 40+ gal · 72–82 °F
Scissortail rasbora
6 in · 40+ gal · 72–79 °F
Rainbow cichlid
6 in · 30+ gal · 72–84 °F
Blue acara
6 in · 40+ gal · 72–82 °F
Swordtail
5.5 in · 29+ gal · 72–82 °F
Keep apart
Discus: No shared temperature: Siamese algae eaters need 72 to 80 °F, discus 82 to 88 °F.
Pea puffer: Pea puffers belong in a tank of their own.
Convict cichlid: Convict cichlids are aggressive towards peaceful fish such as Siamese algae eaters.
Jewel cichlid: Jewel cichlids are aggressive towards peaceful fish such as Siamese algae eaters.
Demasoni cichlid: Demasoni cichlids are aggressive towards peaceful fish such as Siamese algae eaters.
Red zebra cichlid: Red zebra cichlids are aggressive towards peaceful fish such as Siamese algae eaters.
What a Siamese algae eater tank needs
A tank of 29 US gallons or more (such as the 29 gallon) with a tight lid (they jump), and the equipment below.
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Aqueon PRO QuietFlow Power Filter 20
Rated by the maker for up to 30 US gal, which covers a 29 gallon Siamese algae eater tank without being built for a far bigger one.
Aqueon QuietFlow Internal Power Filter 15–30 gal
Rated by the maker for 15–30 US gal, which covers a 29 gallon Siamese algae eater tank without being built for a far bigger one.
Cobalt Aquatics Neo-Therm Pro 100W
Siamese algae eaters need 72 to 80 °F; most homes run cooler, so a heater holds the temperature.
API Freshwater Master Test Kit
Tests ammonia, nitrite, nitrate and pH, the readings that matter most before and after adding Siamese algae eaters.
Seachem Prime 100 mL
Removes chlorine and chloramine from tap water at every water change.
Fluval Edge Thermometer
Shows the water temperature at a glance, so you know it stays within 72 to 80 °F.
More choices, each with the reason it is in or out: Filters for a 29 gallon tank · Heaters for a 29 gallon tank. We don’t list fish food: any good brand of the foods under Diet will do. Plan the whole tank's equipment →
Common Siamese algae eater problems
- Mislabelled lookalikes: the true species has a straight black stripe into the tail fin.
- Older fish eat less algae and more prepared food.
Test the water first whenever fish look unwell: see what your readings mean, then match the symptom. For disease, a vet who treats fish can diagnose it and advise treatment.
More to compare
Sources
Name, origin and adult size checked against Wikipedia: Crossocheilus oblongus. Temperature, pH, hardness, group size, lifespan and minimum tank size are common hobby guidance, not figures from that article. Ranges are the range the species tolerates; aim for the middle. Minimum tank sizes are for an adult group. Drawings are our own; photo credits follow.
Photo credits
Real photographs from Wikimedia Commons, resized and cropped to fit; each is used under the license named.
- Siamese algae eater aleander2137, CC BY-SA 4.0, via Wikimedia Commons
- Angelfish Citron, CC BY-SA 3.0, via Wikimedia Commons
- Rosy barb Kkonstan, CC BY 3.0, via Wikimedia Commons
- Three-spot (blue) gourami Peter Jung, CC BY-SA 3.0, via Wikimedia Commons
- Electric blue acara 5snake5, CC0, via Wikimedia Commons
- Scissortail rasbora Lerdsuwa, CC BY-SA 3.0, via Wikimedia Commons
- Rainbow cichlid Happy Birthday To You!, Public domain, via Wikimedia Commons
- Blue acara Loïc Tremblay, CC BY-SA 3.0, via Wikimedia Commons
- Swordtail Usien, CC0, via Wikimedia Commons
- Discus Patrick Farrelly, Public domain, via Wikimedia Commons
- Pea puffer Beta Mahatvaraj, CC BY-SA 4.0, via Wikimedia Commons
- Convict cichlid S. Olkowicz, CC BY 2.5, via Wikimedia Commons
- Jewel cichlid NasserHalaweh, CC BY-SA 4.0, via Wikimedia Commons
- Demasoni cichlid lee Nachtigal, CC BY 2.0, via Wikimedia Commons
- Red zebra cichlid Maha Dinesh, CC BY-SA 3.0, via Wikimedia Commons
- Kuhli loach Iidkk, CC BY-SA 4.0, via Wikimedia Commons
- Clown loach Vlad Butsky, CC BY 2.0, via Wikimedia Commons
- Dwarf chain loach Stefan Maurer, CC BY-SA 2.0, via Wikimedia Commons
- Reticulated hillstream loach Spiketooth, CC BY-SA 3.0, via Wikimedia Commons
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