Otocinclus Catfish (Otocinclus affinis) – Small, gentle algae-eater ideal for planted aquariums. Keeps leaves spotless while thriving in groups. Great for nano and community tanks.
The Otocinclus Catfish, often affectionately called “Otos,” is a tiny, peaceful freshwater catfish known for its remarkable algae-cleaning abilities. Ideal for planted tanks, nano aquariums, or community setups, Otos are small but mighty helpers, keeping leaves clean and reducing algae buildup without harming plants or other tank inhabitants.
Their delicate size and gentle nature make them a favorite for aquarists seeking a subtle, natural way to maintain tank cleanliness. Active, hardy when kept in groups, and highly compatible with other peaceful species, Otocinclus Catfish bring both utility and charm to your freshwater ecosystem.
🐾 Key Features & Benefits
✔ Algae Cleaning Specialists
Otocinclus Catfish are expert grazers, feeding primarily on soft algae and biofilm. They gently nibble on plant leaves, tank glass, and decorations, helping to maintain a spotless, natural aquarium environment. Unlike larger algae-eaters, Otos are safe for delicate plants and won't disturb the substrate or decor.
✔ Peaceful & Social
These catfish thrive in groups of 4 or more, exhibiting schooling behavior that is fascinating to watch. Their social nature reduces stress and encourages natural activity, adding dynamic movement to the lower levels of your aquarium.
✔ Perfect for Nano & Planted Tanks
Otocinclus Catfish are small and unobtrusive, making them ideal for nano tanks, small community aquariums, and heavily planted setups. Their gentle presence complements mid- and top-level swimmers, creating a balanced and harmonious aquatic environment.
✔ Delicate Appearance & Natural Charm
Featuring a slender, silver body with subtle horizontal stripes and suction-cup mouth, Otos are elegant bottom dwellers. Their graceful grazing behavior adds a natural aesthetic while supporting plant health and tank hygiene.
🌱 Otocinclus Catfish Care & Habitat
Tank & Environment
-
Tank Size: Minimum 10 gallons (larger groups recommended)
-
Temperature: 72–79°F (22–26°C)
-
pH: 6.5–7.5
-
Hardness: Soft to moderately hard water
-
Substrate: Smooth sand or fine gravel; avoid sharp edges to protect their delicate bodies
-
Decor: Driftwood, live plants, and moss create grazing surfaces and hiding spots
Diet & Feeding
-
Primarily algae and biofilm, but benefit from supplemental feeding
-
Offer blanched vegetables (zucchini, cucumber, spinach) or algae wafers for optimal health
-
Feeding in groups encourages natural grazing and reduces competition
Behavior & Social Needs
-
Extremely peaceful and non-aggressive
-
Ideal companions for small tetras, guppies, rasboras, and other community fish
-
Best kept in groups of at least 4–6 for natural schooling behavior and reduced stress
🌿 Aquarium Benefits
-
Provides natural algae control for clean, healthy plants
-
Adds lively activity and interest to the lower tank levels
-
Compatible with nano tanks, planted aquariums, and community setups
-
Gentle, small size ensures no risk to delicate flora or fish
⚠️ Important Notes
-
Keep in sufficient groups for social health and happiness
-
Avoid housing with aggressive or large fish that may prey on Otos
-
Provide clean, well-oxygenated water and maintain consistent water quality
-
Quarantine new fish before introducing them to an established tank
The Otocinclus Catfish is a small but invaluable addition to any freshwater aquarium. Their peaceful demeanor, expert algae-eating ability, and schooling behavior make them perfect for planted tanks, nano aquariums, and vibrant community setups. Watching a group of Otos glide across leaves and décor is both mesmerizing and rewarding, giving you a cleaner, more balanced, and visually appealing aquarium.
Add a school of Otocinclus Catfish to your tank today and enjoy a natural, low-maintenance solution for algae control while enhancing the beauty and harmony of your aquatic world.