Barbs · Pethia conchonius

Rosy barb care guide

Also called: Red barb, Neon rosy barb

The rosy barb is a hardy, active 3.5 in (9 cm) barb from South Asia that likes cooler water, and males flush rosy red. Keep six or more in a 29 gallon (110 L) or larger tank about 40 in (100 cm) long, and skip long-finned tank mates.

Rosy barbs need a tank of at least 29 gallons (110 L), a group of 6 or more, and water at 18–24°C (64–75°F) with a pH of 6–7.8. They grow to about 9 cm (3.5 in) and are peaceful.

Plan a tank with rosy barbsSee all tank mates

Rosy barb quick facts

Scientific namePethia conchonius
FamilyCyprinidae
OriginRivers, lakes and hill streams of India, Pakistan, Nepal and Bangladesh (aquarium fish are farm-bred)
Adult size9 cm (3.5 in)
Minimum tank29 gallons (110 L), at least 100 cm (39 in) long
Temperature18–24°C (64–75°F)
pH6–7.8
Hardness (GH)5–18 dGH
Group size6 or more (shoaling fish)
TemperamentPeaceful
Swims atMiddle
DietOmnivore
Care levelEasy
Lifespan4–6 years
Safe with shrimp?No, eats shrimp
Safe with plants?Mostly (nibbles soft plants)
  • Cold-water species: no heater needed in most homes.

Tank setup

A group of six needs at least 29 gallons (110 L) in a tank about 40 in (100 cm) long, because these are fast, constant swimmers. Plant the sides with tough or fast-growing plants and keep the middle open. A dark substrate and some floating plants make the colors richer. Strong, steady filtration handles their appetite.

How many rosy barbs in a tank?

The smallest common tank that suits rosy barbs is a 55 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.

TankRosy barbs (alone)
3 gallonToo small
5 gallonToo small
10 gallonToo small
15 gallonToo small
20 gallonToo small
20 gallon longToo small
29 gallonToo small
40 gallonToo small
55 gallon6–18
75 gallon6–25
125 gallon6–42

What you need for rosy barbs

Sized for a 29 gallon tank, the smallest common size that suits a group of 6 rosy barbs. For a different tank or a mix of fish, use the stocking calculator for a list sized to your plan.

Tank and equipment

Food and extras for rosy barbs

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Water parameters

They are comfortable at 18–24 °C (64–75 °F), so many heated homes need little or no tank heating. Aim for pH 6.0–7.8 and around 5–18 dGH; most tap water suits them. Keep nitrate low with weekly partial water changes.

Best tank mates for rosy barbs

These popular species share rosy barbs' water needs and temperament. See the full list of 28 good matches.

Avoid keeping rosy barbs with

  • Cherry shrimp: Rosy barb eats small shrimp like cherry shrimp.
  • Oscar: Oscar can eat rosy barbs: they're small enough to fit in its mouth once it's grown.
  • Boesemani rainbowfish: They need different temperatures: Rosy barb 18–24°C (64–75°F), boesemani rainbowfish 26–29°C (79–84°F).
  • Chinese algae eater: Chinese algae eater is aggressive and will bully or injure peaceful rosy barbs.
  • Clown loach: They need different temperatures: Rosy barb 18–24°C (64–75°F), clown loach 25–30°C (77–86°F).
  • Convict cichlid: Convict cichlid is aggressive and will bully or injure peaceful rosy barbs.

Feeding

Rosy barbs are greedy omnivores. Feed a quality flake or small pellet with plenty of vegetable content, plus frozen or live daphnia, brine shrimp and bloodworm. They also graze algae, including some hair algae, and blanched spinach or other greens helps keep them off soft plants.

Behavior

In a group of six or more they are busy but peaceful fish that mostly ignore other species. Small groups get nervous and start nipping, and their nonstop activity can stress shy or slow fish. Good tank mates are other robust barbs, danios, larger tetras, loaches, corydoras and other cool-tolerant fish such as gold barbs. Avoid bettas, fancy guppies, angelfish and long-finned rosy barb strains.

Breeding

Males are slimmer and turn deep rosy red with dark fin tips when ready to spawn; females are fuller-bodied and olive-gold. They scatter lots of eggs over fine-leaved plants and give no care. Spawn one male with two females in a separate tank with marbles or java moss on the bottom, remove the adults afterward and keep the tank dim. Eggs hatch in about 1–2 days and the fry start on infusoria.

Tips from experienced keepers

  • They do well in unheated tanks in most homes, so they pair nicely with other cool-water fish.
  • Choose tough plants like java fern, anubias and vallisneria. Soft or fine-leaved plants may get eaten.
  • A bigger group means less nipping. Eight or more is ideal if the tank is large enough.
  • Adult rosy barbs will eat dwarf shrimp, so do not plan on keeping them with cherry shrimp.
  • Long-finned rosy barbs have the same care needs but are slower, so do not mix them with nippy fish.

Frequently asked questions

Do rosy barbs need a heater?

Often not. They are comfortable at 18–24 °C (64–75 °F), so a tank in a heated room usually stays in range. Add a heater if the room drops below about 18 °C (64 °F).

Are rosy barbs fin nippers?

They can be, mostly when kept in small groups. In a group of six or more they are fairly peaceful, but long-finned fish like bettas and fancy guppies are still at risk.

How big do rosy barbs get?

Most reach about 3–3.5 in (8–9 cm) in home tanks, and some grow a little bigger. Plan the tank for adults, not the small juveniles sold in stores.

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.