Otocinclus (or "otos") are the planted tank hobbyist's secret weapon, tiny, peaceful suckermouth catfish that methodically graze soft algae (diatoms, green spot algae, biofilm) from plant leaves, glass, and wood without damaging the plants themselves. They are extremely social, keep in groups of 6+ as isolated individuals refuse food and die. ⚠️ Most otos sold in stores are wild-caught and arrive stressed and parasite-laden; quarantine for 4+ weeks and add cucumber or zucchini immediately. They are sensitive to poor water quality. Supplement diet with algae wafers and blanched vegetables.
| Max Size | 5 cm |
| Temperature | 21–26°C |
| pH Range | 6.0–7.5 |
| Min Tank Size | 60L |
| Care Level | Intermediate |
| Origin | South America, Peru, Colombia, Brazil |
Completely peaceful with all tank mates. Safe with even small shrimp. One of the best algae-control fish for planted tanks.
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