Common carp

Water parameters

Minimum tank: 1000 L per individual at harvest size.

Feed and growth

Feed protein

28% target

Daily feed (warm)

1.80% of body weight

Daily feed (cool)

0.60% of body weight

Max density

50 g per litre

A 8000 g adult eats about 144.0 g of feed per day at optimum. 10 fish at adult size: ~1440 g daily.

Legality

Rules vary by jurisdiction and change over time. Verify with your local fisheries or wildlife authority before stocking.

Unlisted jurisdictions default to "check local regulations".

Origin and habitat

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

temperate (handles seasonal swings)

USDA zones

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

Heating needed

no

Cooling needed

no

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 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