Tankwise

Small, peaceful algae eaters for planted tanks. Best added to a mature tank with a group and plenty of grazing surface.

  • Temperature22–27 °C
  • pH6–7.5
  • Minimum tank50 L
  • DifficultyIntermediate
FoodAlgae/biofilm + blanched veg
FeedingDaily grazing + algae wafer
Water change25% weekly

Behaviour and habits

A small, peaceful algae-grazing catfish that clings to leaves, wood and glass and works in loose groups. It is shy and mostly active once settled, and best kept in a group of six or more.

What to feed, and how often

A specialised grazer that lives on aufwuchs — algae and biofilm — and often starves in a spotless new tank. Supplement with blanched courgette, spinach or an algae wafer, but let it graze naturally too.

Water changes and maintenance

Keep the water clean and well oxygenated; do 25% weekly changes. Many otos are lost in the first weeks, so add them to a tank that has been running a while.

Care and how easy it is

Not a fish for a brand-new tank: buy it fat, add it to a mature planted tank, and ensure constant grazing.

Lifespan

With good conditions and steady water quality, this species typically lives around 3–6 years in a home aquarium; some individuals live longer.

Common health problems

The main danger is starvation, and parasites in new stock; they arrive thin and fade quickly.

If it gets sick

If an oto looks sunken-bellied, feed blanched vegetables and consider a deworming treatment, but do not over-medicate — they are sensitive to medicines. Quarantine new ones and observe for a few weeks.

Good tank mates

Neon tetraIntermediate; stable group aquarium
Neon tetraParacheirodon innesi
  • 21-25 C
  • pH 6.0-7.5
  • 60 L+; 60 x 30 cm base
Tetras & rasboras | Peaceful shoaler | Omnivore
Cherry shrimpBeginner
Cherry shrimpNeocaridina davidi
  • 18–26°C
  • pH 6.5–8
  • 20 L+
Shrimp & snails · Peaceful · Omnivore
BettaBeginner with a prepared single-fish tank
BettaBetta splendens
  • 24-26 C
  • pH 6.5-7.5
  • 40 L+; 45 x 30 cm base
Bettas & gouramis | Territorial | Carnivore
CorydorasBeginner
CorydorasCorydoras paleatus
  • 20–26°C
  • pH 6–7.8
  • 60 L+
Catfish · Peaceful · Omnivore
Ram cichlidAdvanced
Ram cichlidMikrogeophagus ramirezi
  • 25–29°C
  • pH 5–7
  • 70 L+
Cichlids · Peaceful · Omnivore

Best avoided with

Similar species

Bristlenose plecoBeginner
Bristlenose plecoAncistrus cirrhosus
  • 23–27°C
  • pH 6–7.5
  • 80 L+
Catfish · Peaceful · Herbivore
Clown plecoBeginner
Clown plecoPanaqolus maccus
  • 23–28°C
  • pH 6.5–7.5
  • 80 L+
Catfish · Peaceful · Herbivore
Common plecoAdvanced
Common plecoHypostomus plecostomus
  • Confirm species before setting water targets
  • 180 x 75 cm base or larger for a large P. pardalis; editorial plan
Catfish | Trade-name identity caution | Not a cleaning tool

Compare at a glance

ParametersOtocinclusBristlenose plecoClown pleco
Parameters
Temp22–27 °C23–27 °C23–28 °C
pH6–7.56–7.56.5–7.5
GH2–12 °dGH2–15 °dGH4–15 °dGH
Min. tank50 L80 L80 L
Size4 cm12 cm10 cm
DietHerbivoreHerbivoreHerbivore
TemperamentPeacefulPeacefulPeaceful
DifficultyIntermediateBeginnerBeginner

Care guides

GuideThe Best Beginner Aquarium PlantsLive plants are not hard — some are almost unkillable. These easy, low-light species use up waste, look natural and give fish cover, with no special equipment.GuideHow to Lower Nitrate in an AquariumNitrate is the quiet end of the nitrogen cycle. It is far less toxic than ammonia, but it builds up and is the usual reason algae wins. Here is how to bring it down.

New to the words? See the aquarium glossary.

Sources and research notes

Parameters are typical ranges for the species in home aquariums and vary with the individual fish and the water you use.