Tilapia Tank Stocking

Tilapia Stocking Density Calculator (Oreochromis niloticus)

Nile tilapia is the most farmed fish in Brazil and makes up roughly 60% of national aquaculture production. How densely you can stock depends a lot on the system. Intensive net cages (tanques-rede) handle 30–50 kg/m³ at harvest because the water is constantly renewed, whereas earthen ponds (viveiros escavados) stay safe around 10–15 kg/m³. Convert litres to cubic metres with m³ = L ÷ 1000, multiply by your target density for total biomass, then divide by average individual weight to estimate how many fish that is.

A full production cycle runs 6–8 months before the fish hit the commercial size of 800 g–1 kg, assuming the water sits at 25–30°C with dissolved oxygen above 4 mg/L. Below 18°C the fish stop feeding. Above 35°C oxygen solubility crashes, and either way you get stressed fish and higher mortality. Start on the low side and only push the density up once you've watched O₂, ammonia and conversion rates for a while.

Applications

Small and mid-scale fish farmers reach for this when laying out ponds and net cages. So do EMBRAPA Pesca e Aquicultura technicians sizing demonstration units, agronomy and zootechnics students working through projects, and pesque-pague operators trying to balance stocking against sport fishing pressure.

FAQ

Can I stock 50 kg/m³ in any tank? Only in net cages or RAS with mechanical aeration and continuous water exchange. A static pond will crash from low oxygen well before it ever reaches that density.

How many fingerlings per 1000 L? Figure on 100–150 fingerlings of 1 g to start, thinned down to 30–50 adults of 800 g by harvest, if you're working with pond conditions (10–15 kg/m³).

What is the feed conversion ratio? A well-managed tilapia farm lands an FCR of 1.4–1.7 (kg of feed per kg of fish), which is among the best you'll find for any farmed freshwater species.