Nile tilapia

Water parameters

Minimum tank: 200 L per individual at harvest size.

Feed and growth

Feed protein

32% target

Daily feed (warm)

1.50% of body weight

Daily feed (cool)

0.80% of body weight

Max density

60 g per litre

A 600 g adult eats about 9.0 g of feed per day at optimum. 10 fish at adult size: ~90 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

Oreochromis niloticus is an African cichlid native to the Nile basin, the rift lakes and rivers of East and West Africa, and the Levant. It is the most farmed tropical fish in the world and among the top freshwater aquaculture species overall, with output around 4 million tonnes a year, raised on every continent but Antarctica. Its success rests on toughness: it handles brackish water to roughly 15 to 18 ppt, oxygen down near 0.5 mg/L (though it stresses below 3), temperatures from about 14 to 36 C, and a wide pH band. It is a maternal mouthbrooder, the female carrying eggs and fry in her mouth, and it breeds freely and grows fast, reaching a harvest size of 400–600 g in six to nine months in warm conditions; the largest wild fish reach about 60 cm and over 4 kg. Escaped and released fish have set up feral populations across the tropics and subtropics, and the species readily hybridizes with other Oreochromis, which makes it one of the most invasive freshwater fish and the main reason for the stocking restrictions it faces in many places.

Climate and outdoor ponds

Climate

tropical (needs warm water year-round)

USDA zones

10–13 (winter low around -1°C or warmer)

Heating needed

yes

Cooling needed

no

Care notes

The workhorse of warm-water aquaponics. Nile tilapia turn feed into flesh efficiently, with feed conversion around 1.4 to 1.8 on commercial pellet, and they shrug off the parameter swings common in home systems. Below about 18°C they stop eating and below 12°C they die, so temperate systems need a heater or an insulated greenhouse to carry them through winter. The biggest management headache is breeding: mixed-sex groups spawn constantly, pouring energy into eggs instead of growth and flooding the system with fry. Commercial farms run all-male stock produced by hormonal sex reversal (methyltestosterone-treated fry), temperature treatment, or YY-male breeding, and improved lines such as the GIFT strain grow markedly faster than older stock. Home keepers who cannot get sex-reversed fingerlings often run mixed-sex tanks and cull juveniles or accept slower growth. Stocking in aquaponics is usually 20 to 40 g/L, higher with strong biofiltration and aeration. Tilapia are legal to culture in most US states but banned or restricted in some, including cold states where escape risk is low, and prohibited across Australia, so check local rules before buying. Feed a 32 to 36 percent protein tilapia or catfish pellet at roughly 1 to 3 percent of body weight a day, adjusted for temperature and size.

Further reading

• Fish for aquaponics: tilapia vs everything else