Bristlenose pleco care guide
Also called: Bristlenose catfish, Bushynose pleco, Bushy nose pleco, Common bristlenose, Ancistrus
The bristlenose pleco is a small, hardy catfish that stays around 4–5 inches (12 cm) and grazes algae day and night. It's one of the best algae eaters for tanks of 20 gallons (76 L) or more, but it needs driftwood, a cave and vegetables, not just leftover algae.
Bristlenose plecos need a tank of at least 20 gallons (76 L), and water at 22–26°C (72–79°F) with a pH of 6–7.5. They grow to about 12 cm (4.7 in) and are peaceful.
Plan a tank with bristlenose plecosSee all tank mates
Bristlenose pleco quick facts
| Scientific name | Ancistrus cf. cirrhosus |
|---|---|
| Family | Loricariidae |
| Origin | South America (aquarium strains are captive-bred and their exact wild origin is unclear) |
| Adult size | 12 cm (4.7 in) |
| Minimum tank | 20 gallons (76 L), at least 60 cm (24 in) long |
| Temperature | 22–26°C (72–79°F) |
| pH | 6–7.5 |
| Hardness (GH) | 2–15 dGH |
| Group size | Alone (only one male) |
| Temperament | Peaceful; males fight each other |
| Swims at | Bottom |
| Diet | Omnivore |
| Care level | Easy |
| Lifespan | 5–10 years |
| Safe with shrimp? | Yes, shrimp-safe |
| Safe with plants? | Mostly (nibbles soft plants) |
Tank setup
One bristlenose needs at least a 20-gallon (76 L) tank about 24 in (60 cm) long, and more room for a pair or group. Give it driftwood to graze and a cave or two to hide in during the day. Good filtration and some current help, since plecos make a fair amount of waste.
How many bristlenose plecos in a tank?
The smallest common tank that suits bristlenose plecos is a 20 gallon. Here is roughly how many fit in each size when they are the only fish, based on adult size and waste output. Leave room if you want tank mates.
| Tank | Bristlenose plecos (alone) |
|---|---|
| 3 gallon | Too small |
| 5 gallon | Too small |
| 10 gallon | Too small |
| 15 gallon | Too small |
| 20 gallon | Up to 3 |
| 20 gallon long | Up to 3 |
| 29 gallon | Up to 5 |
| 40 gallon | Up to 6 |
| 55 gallon | Up to 9 |
| 75 gallon | Up to 13 |
| 125 gallon | Up to 21 |
Numbers are bioload limits only. Males fight, so keep one male unless the tank is large and well planned.
What you need for bristlenose plecos
Sized for a 20 gallon tank, the smallest common size that suits bristlenose plecos. For a different tank or a mix of fish, use the stocking calculator for a list sized to your plan.
Tank and equipment
- 20 gallon aquarium (tank or kit) (opens Amazon in a new tab)Bigger tanks are more stable and easier for beginners. How to choose
- Aquarium stand for 20 gallons (opens Amazon in a new tab)The water alone weighs about 167 lb (76 kg), before glass, gravel and rock. How to choose
- Adjustable heater, 50 W (opens Amazon in a new tab)Holds about 75 °F (24 °C) in a room at 65 °F (18 °C). How to choose
- Aquarium thermometer (opens Amazon in a new tab)Check it daily: heaters can fail stuck on or off. How to choose
- Hang-on-back filter rated 80–120 GPH (opens Amazon in a new tab)Community tank: 4–6 times the tank volume per hour. How to choose
- About 35 lb of aquarium gravel (opens Amazon in a new tab)Enough for a layer about 2 in (5 cm) deep. Smooth gravel suits most community fish. How to choose
- Water conditioner (dechlorinator) (opens Amazon in a new tab)Removes chlorine and chloramine from tap water. Seachem Prime is a popular, concentrated choice. How to choose
- Liquid test kit (ammonia, nitrite, nitrate, pH) (opens Amazon in a new tab)Liquid kits are more accurate than strips. The API Freshwater Master Test Kit is the common choice. How to choose
- Gravel vacuum (siphon) (opens Amazon in a new tab)Cleans the gravel and does the water change in one go. How to choose
- LED aquarium light, about 24 in long (opens Amazon in a new tab)Match the light to the tank length. Basic LEDs grow easy plants. How to choose
Food and extras for bristlenose plecos
- Sinking pellets or wafers (opens Amazon in a new tab)Bottom feeders need food that reaches the floor.
- Aquarium driftwood (opens Amazon in a new tab)Plecos graze on it, and it softens water slightly.
- Caves and hides (opens Amazon in a new tab)Gives shy and territorial fish their own space.
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Water parameters
Keep it at 22–26°C (72–79°F), pH 6.0–7.5 and soft to moderately hard water. Captive-bred bristlenose adapt well to most tap water as long as it is clean and well oxygenated. Weekly partial water changes keep nitrate low.
Best tank mates for bristlenose plecos
These popular species share bristlenose plecos' water needs and temperament. See the full list of 89 good matches.
Betta fish
6.5 cm (2.6 in) · 24–28°C (75–82°F)
Cherry shrimp
3 cm (1.2 in) · 20–27°C (68–81°F)
Nerite snail
2.5 cm (1 in) · 22–27°C (72–81°F)
Guppy
5 cm (2 in) · 22–27°C (72–81°F)
Dwarf gourami
7.5 cm (3 in) · 24–28°C (75–82°F)
Neon tetra
3.5 cm (1.4 in) · 21–25°C (70–77°F)
Zebra danio
5 cm (2 in) · 18–25°C (64–77°F)
Angelfish
15 cm (5.9 in) · 24–29°C (75–84°F)
Avoid keeping bristlenose plecos with
- Chinese algae eater: Chinese algae eater is aggressive and will bully or injure peaceful bristlenose plecos.
- Convict cichlid: Convict cichlid is aggressive and will bully or injure peaceful bristlenose plecos.
- Discus: They need different temperatures: Bristlenose pleco 22–26°C (72–79°F), discus 28–30°C (82–86°F).
- German blue ram: They need different temperatures: Bristlenose pleco 22–26°C (72–79°F), german blue ram 27–30°C (81–86°F).
- Jack Dempsey: Jack Dempsey is aggressive and will bully or injure peaceful bristlenose plecos.
- Pea puffer: Pea puffer is aggressive and will bully or injure peaceful bristlenose plecos.
Feeding
Mostly a grazer, but it can't live on the algae in your tank alone. Feed sinking algae wafers or gel food daily, with blanched zucchini, cucumber, peas or green beans a few times a week. Add a little meaty food like frozen bloodworms now and then. Feed after lights out, when it is most active.
Behavior
Peaceful toward most community fish and ignores fish higher up in the tank. Males claim caves and chase other males and similar-shaped plecos, so keep one male per tank unless it is large with many hides. It may push other bottom fish away from its spot but rarely harms them. Generally safe with shrimp and snails.
Breeding
One of the easiest plecos to breed. Males grow bushy tentacles on the snout; females have few or none. The female lays a clump of orange eggs in the male's cave, and he guards and fans them until the fry leave. Fry graze algae and biofilm and eat crushed wafers and soft vegetables.
Tips from experienced keepers
- Add driftwood. Bristlenose rasp it and graze the biofilm that grows on it.
- Drop food in after lights out so faster fish don't eat it first.
- Keep one male per cave. Two males in a small tank will fight over territory.
- Check its belly: it should look slightly rounded, not sunken.
- If yours nibbles sword plants or soft leaves, switch to tough plants like anubias and java fern.
Frequently asked questions
How big do bristlenose plecos get?
Most adults reach about 4–5 inches (10–13 cm). Males are usually a little bigger than females and grow the bushy snout tentacles.
Can you keep two bristlenose plecos together?
Yes. A male and female, or one male with several females, works well. Two males need a bigger tank with separate caves, or they will fight.
Do bristlenose plecos eat shrimp?
No. They are generally safe with dwarf shrimp and snails. They graze algae and biofilm and eat food that sinks to the bottom.
Sources
We checked these references when writing this page. Values are for healthy long-term keeping, not survival limits. Last reviewed 2026-10-13. See our editorial policy.