Chinese Algae Eater
Chinese Algae Eater
Chinese Algae Eater (Gyrinocheilus aymonieri) is one of the most widely sold and frequently misunderstood aquarium fish. Juveniles are active algae grazers that efficiently clean algae from glass and hardscape. They are fast, hardy, and effective at their job. However, their behavior changes significantly as they mature — understanding this transition is important for long-term success.
Feeding & Care Tip: Hikari Mini Algae Wafers placed on flat surfaces are the ideal staple. Supplement with blanched vegetables and Sera Vipan Tropical Flakes for omnivorous nutrition. As adults, varied feeding reduces food-seeking aggression toward tankmates.
Native to fast-flowing, rocky rivers of Southeast Asia — the Mekong, Chao Phraya, and related drainages of Thailand and Laos. In the wild it rasps algae from rocks in fast-flowing water. The aquarium adaptation has produced a fish that is very hardy and effective when young.
Note on adult behavior: Juvenile Chinese Algae Eaters are effective algae grazers, but as they mature they often become territorial and may attach to the sides of larger flat-bodied fish to rasp their mucus coat. This behavior increases with age and is most pronounced in fish over 3 inches. Choose tankmates accordingly — avoid large flat-bodied fish like angelfish or discus in the long term. Juvenile Chinese Algae Eaters work excellently as a cleaning crew in established aquariums. As they grow (typically over 3 inches, around 1–2 years), watch for changes in behavior and plan for either rehoming or appropriate large tankmates.
For aquarists who want a reliable long-term algae eater, the Siamese Algae Eater (Crossocheilus oblongus) remains effective and peaceful into adulthood and is generally a better long-term choice. The Chinese Algae Eater is at its best and most useful as a juvenile cleaner.
Care & Ideal Parameters
| Difficulty | Easy |
| Temperament | Peaceful as juvenile — potentially territorial as adult |
| Typical Adult Size | 10 inches (25 cm) |
| Min. Group Size | Singly as adult |
| Ideal Temp | 72–82°F (22–28°C) |
| Ideal pH | 6.0–8.0 |
| Ideal GH | 5–20 dGH |
| Ideal KH | 2–10 dKH |
| Staple Food | Hikari Mini Algae Wafers; blanched vegetables |
| Treat / Supplement | Sera Vipan Tropical Flakes |
| Origin | Mekong and Chao Phraya drainages, Thailand and Laos |
| Notes | Effective juvenile algae grazer. Adults may become territorial and attach to flat-bodied fish. Behavior change typically begins after 3 inches. Siamese Algae Eater is better long-term algae control option. |
