Bristlenose pleco
Ancistrus cirrhosus
easy careOverview
The bristlenose pleco (Ancistrus cirrhosus) is the sensible pleco — the one that actually fits a normal aquarium. Where the common pleco balloons to 30–45 cm, the bristlenose tops out around 10–13 cm, so it’s a lifelong resident of a mid-sized tank rather than a fish that will quickly outgrow it. Mature males grow the fleshy “bristles” on the snout that give the fish its name. Peaceful, hardy and a genuine algae grazer, it’s the pleco most keepers should choose.
Tank & water
A single bristlenose suits 75 litres (20 gallons) or more. Keep 22–27 °C with a heater and a good filter — plecos are messy and appreciate strong filtration and oxygen.
- Driftwood and a cave: essential for rasping and hiding.
- Steady maintenance: they produce a lot of waste, so keep up water changes — see aquarium maintenance.
- Don’t overstock: factor its bioload in — read how many fish in an aquarium.
Feeding
Bristlenose plecos are largely herbivores. Feed sinking algae wafers plus blanched vegetables — courgette, cucumber, spinach and de-shelled peas — and provide driftwood to rasp on. A little sinking protein now and then is fine. Browse the fish food hub and our best fish food picks. Feed in the evening, as they are most active after lights-out, and remove uneaten vegetables the next day before they foul the water.
Tankmates
Peaceful and unbothered by other fish, the bristlenose suits almost any community — tetras, rasboras, corydoras, gouramis, bettas and cherry shrimp. Males can be territorial with other plecos, so give them space or keep just one. It also coexists calmly with peaceful bottom-dwellers like the kuhli loach.
Frequently asked questions
The bristlenose pleco is the algae-grazer that actually belongs in a home aquarium. Give it driftwood, vegetables and good filtration and it will graze away peacefully for many years.
Bristlenose pleco — frequently asked questions
How big does a bristlenose pleco get?
Only about 10–13 cm — which is exactly why it's the sensible pleco. Unlike the common pleco, which reaches 30–45 cm and outgrows most tanks, the bristlenose stays small enough for a standard 75-litre aquarium for life.
Does a bristlenose pleco keep the tank clean?
It grazes algae well and helps, but it is not a cleaning machine. It still produces plenty of waste and needs its own food — algae wafers and vegetables — plus driftwood to rasp on. Don't rely on it to replace water changes.
Do bristlenose plecos need driftwood?
Yes, ideally. They rasp on wood, which aids their digestion and gives them somewhere to hide. A piece of driftwood plus a cave will keep a bristlenose much happier and more settled.
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