Nile tilapia

Quick facts

Adult size

35 cm, 600 g typical harvest weight

Days to harvest

180 to 270 days from fingerling

Lifespan (max)

up to 10 years

Diet

omnivore

Temperature class

warm-water

Difficulty

beginner

Water parameters

Temperature range

22–32°C (optimum 28°C)

pH

6.5 to 8.5

Hardness

5 to 25 dGH

Minimum tank

200 L per individual at harvest size

Feed and growth

Feed protein

32% target

Daily feed (warm water)

1.50% of body weight per day

Daily feed (cool water)

0.80% of body weight per day

Max stocking density

60 g per litre of system water

A 600g adult eats about 9.0 g of feed per day at optimum temperature. For a roster of 10 fish at adult size, that's around 90 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 Nile River basin, the Levant, and East African rift lakes. The species (Oreochromis niloticus) is now farmed on every continent except Antarctica, making it the most widely cultured freshwater fish in the world after the carp family. Wild populations tolerate a remarkable range of conditions: brackish water up to 15 ppt, dissolved oxygen as low as 0.5 mg/L (though they stress below 3 mg/L), temperatures from 14°C to 36°C, and pH from 5 to 11. This adaptability is exactly why they dominate global aquaculture. They're also prolific breeders and fast growers, reaching harvest size (400–600 g) in 6-9 months under optimal conditions. Feral populations have established outside their native range across tropical and subtropical regions worldwide, making Nile tilapia one of the most invasive freshwater fish species. This invasive potential is the primary reason for stocking restrictions in many jurisdictions.

Climate and outdoor ponds

Climate classification

tropical (needs warm water year-round)

Outdoor pond zones (USDA)

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

Heating in a temperate climate

Required for year-round operation

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

The workhorse of warm-water aquaponics. Nile tilapia convert feed to flesh efficiently (FCR 1.4-1.8 on commercial pellets) and tolerate the parameter swings that happen in home systems. Below 18°C they stop eating; below 12°C they die. Most aquaponics systems in temperate climates need a water heater or insulated greenhouse to keep tilapia through winter. The single biggest management issue is reproduction: mixed-sex populations breed constantly, diverting energy from growth into egg production and overwhelming the system with fingerlings. Commercial operations use all-male populations produced by hormonal sex reversal (methyltestosterone treatment of fry) or YY-male breeding programs. Home aquaponics keepers who can't source sex-reversed fingerlings often run mixed-sex systems and cull juveniles regularly, or accept slower growth rates. Stocking density in aquaponics ranges from 20-40 g/L depending on filtration capacity. Higher densities are possible but require excellent biofiltration and aeration. Tilapia are legal to culture in most US states but some (including several cold-climate states where escape risk is low) still restrict or prohibit them. Check state regulations before ordering fingerlings. Feed: 32-36% protein commercial tilapia or catfish pellet. Feed 1-3% of body weight daily, adjusted by temperature and growth stage.

Further reading

• Fish for aquaponics: tilapia vs everything else