Rosy barb

Quick facts

Adult size

14 cm

Lifespan

can live up to 8 years

Tank zone

mid

Temperament

peaceful

Difficulty

beginner

Schooling

recommended 6+ (critical minimum 5, thrives at 8+)

Water parameters

Temperature

16–26°C

pH

6.0 to 8.0

Hardness

2 to 18 dGH

Tank requirements

Minimum volume

130 L

Minimum length

90 cm

Flow

moderate

Lighting

moderate

Substrate

any

Open swimming room

needed

Lid

required - jumper

Feeding

Diet: omnivore, feeds primarily at the mid.

Omnivore that eats everything. Flake, pellets, frozen bloodworm, frozen brine shrimp, frozen daphnia, blanched vegetables (peas, zucchini, spinach), algae wafers, and live food. They graze on algae in addition to accepting prepared foods. Feed twice daily. The rosy-red coloring in males improves with carotenoid-rich foods (brine shrimp, krill, spirulina). Overfeeding is easy because they eat relentlessly; moderate portions keep them fit.

Vegetable matter required (algae wafers, blanched zucchini, spinach).

Compatibility

• Hardy, active schooling barb. Peaceful by barb standards; minimal nipping behavior. Works with most medium-sized community fish.
• Groups of 6+ bring out the best coloring and behavior. Males in breeding condition turn deep red-pink and compete for female attention with fin displays.
• Tolerates cooler water (16–25°C), making them one of the few tropical barbs suitable for unheated tanks in temperate climates. Good companions for goldfish (in large enough tanks), white clouds, and other subtropical species.
• Larger than many common barbs at 10–14 cm for mature adults. They need more space than their juvenile size suggests. A group of adults needs 150 L.

Habitat

Native to rivers, lakes, and ponds in the subtropical regions of Bangladesh, India (West Bengal, Assam), and Nepal. Found in slow to moderately flowing water with sandy or muddy substrates and bankside vegetation. The species (Pethia conchonius) was described by Hamilton in 1822 and has been in the aquarium hobby since the early 1900s. Males in breeding condition develop a deep rosy-red body that gives the species its common name. Outside of breeding season, males are more olive-gold. Females are always olive to silver-gold. Several color variants have been line-bred: long-finned, gold (neon rosy barb), and GloFish variants. Adult size is larger than many keepers expect: 10–14 cm for well-grown adults in appropriate tanks. This makes them mid-sized fish, not small community fish. The subtropical origin means they tolerate temperatures from 16–25°C, making them suitable for unheated indoor tanks in mild climates and even outdoor ponds in temperate regions during summer. All stock is commercially bred in massive quantities.

Breeding

Easy egg scatterer that breeds prolifically. Condition males and females separately with frozen food for a week. The breeding tank needs fine-leaved plants or spawning mops and clean water; temperature and chemistry are not critical. Males in breeding condition turn deep red and chase females aggressively. Spawning happens in the morning, usually in bursts among plant material. The pair scatters 200-400 eggs. Eggs are semi-adhesive and settle on plant surfaces and the substrate. Adults eat eggs immediately, so remove them after spawning. Eggs hatch in 30-36 hours. Fry become free-swimming in 2-3 days and take baby brine shrimp. Growth is fast; juveniles reach 3–4 cm within 2 months. Rosy barbs are bred commercially in enormous quantities in outdoor ponds. Home breeding is a simple project suitable for beginners.

Common problems

Size surprise is the main issue for new keepers. A 4 cm juvenile in the store doesn't convey the 12 cm adult that arrives in a year. A group of 6 adult rosy barbs needs a proper mid-sized tank, not the 60-liter nano they started in. Health problems are exceptionally rare. This is one of the hardiest freshwater fish in the hobby. Ich is uncommon except in severely stressed new arrivals. They tolerate a wide range of water conditions and medications. The main cosmetic concern is that males only show the full rosy-red color during breeding condition or when kept in mixed-sex groups with competition. Males in all-male tanks or males not in breeding condition can look plain olive-gold.

Outdoor pond suitability

This species is suited to outdoor ponds, not just indoor aquariums.

Climate classification

subtropical

Outdoor pond zones (USDA)

8 to 12 (winter low around -12°C or warmer)

Outside the zone range, this species can still be kept indoors. Within the zone, an outdoor pond at least 60 cm deep usually has enough thermal mass to overwinter the species, though local frost depth and surface freezing matter.

Bioload

Bioload coefficient: 2.5 (active mid-sized barb; significantly larger than zebra danio at adult size).

Bioload coefficients are calibrated against the neon tetra as the anchor (1.0). See the methodology page for the formula and how each value was derived.

Further reading

• How to cycle a fish tank
• Stocking ideas by tank size