Common carp

Quick facts

Adult size

70 cm, 8000 g typical harvest weight

Days to harvest

365 to 730 days from fingerling

Lifespan (max)

up to 38 years

Diet

omnivore

Temperature class

warm-water

Difficulty

beginner

Water parameters

Temperature range

3–32°C (optimum 25°C)

pH

6.5 to 9

Hardness

5 to 30 dGH

Minimum tank

1000 L per individual at harvest size

Feed and growth

Feed protein

28% target

Daily feed (warm water)

1.80% of body weight per day

Daily feed (cool water)

0.60% of body weight per day

Max stocking density

50 g per litre of system water

A 8000g adult eats about 144.0 g of feed per day at optimum temperature. For a roster of 10 fish at adult size, that's around 1440 g of feed daily.

Legality

Aquaculture and possession rules vary by jurisdiction and change over time. This table reflects regulations as of the verified date on each row. Verify with your local fisheries or wildlife authority before stocking.

Jurisdictions not listed here default to "check local regulations". A non-listing is not a green light; rules in your specific county or municipality may apply.

Habitat and origin

Native to the Danube River basin and Central Asian waterways. The most widely cultured freshwater fish in the world by tonnage, with a production history spanning over 2,000 years in China and over 600 years in Europe. Found in slow-moving rivers, lakes, and ponds with muddy substrates and warm water. The species (Cyprinus carpio) is the ancestor of koi and goldfish. Wild-type common carp are deep-bodied, bronze to olive-brown, fully scaled fish. Several domesticated varieties exist: mirror carp (large scattered scales), leather carp (few or no scales), and various Asian cultivated strains. The species tolerates extremely wide environmental conditions: temperatures from near-freezing to 35°C, dissolved oxygen below 1 mg/L (briefly), salinity up to 5 ppt, and pH from 6 to 9. This tolerance, combined with fast growth and easy reproduction, is why it became the world's first aquaculture species and remains the most produced.

Climate and outdoor ponds

Climate classification

temperate (handles seasonal swings)

Outdoor pond zones (USDA)

3 to 12 (winter low around -40°C or warmer)

Heating in a temperate climate

Not required (handles seasonal cool periods)

Cooling in a temperate climate

Not required

Zone bounds reflect year-round outdoor pond viability with no active heating. Anywhere outside the bounded zone, the species can still be kept in an indoor heated tank or a seasonally-managed system. Verify your specific microclimate, as a sheltered yard zone can run a half-zone warmer than the regional rating.

Care notes

A viable aquaponics species in regions where carp is culturally valued as food (Central and Eastern Europe, much of Asia) or where other species are restricted. In the US, Australia, and many tropical countries, common carp is a notorious invasive species and stocking is regulated or prohibited. Check local regulations carefully. Where legal, carp offer the easiest possible aquaponics fish: they eat anything (commercial pellet, grain, kitchen scraps, aquatic plants), tolerate terrible water quality, grow to harvest size (500–1 g) in 12-18 months under warm conditions, and are essentially disease-proof under culture conditions. FCR on pellet is 1.5-2.0. Stocking density can be high (20-40 g/L) because they tolerate crowding better than most species. The main issue for Western aquaponics keepers is market acceptance: carp is not popular table fare in North America or Australia, so growing a fish nobody wants to eat defeats the purpose. In Eastern European, Middle Eastern, and Asian contexts, this isn't an issue. Feed: any commercial fish pellet (28-32% protein) or grain-based feed.

Further reading

• Aquaponics water chemistry: balancing pH for fish and plants
• Fish for aquaponics: tilapia vs everything else