Question 1

What is a good feed conversion ratio (FCR) in aquaculture?

Accepted Answer

FCR = total feed fed (kg) / total fish weight gain (kg). For salmon, a good FCR is 1.1-1.3 (1.1-1.3 kg feed per 1 kg gain). Tilapia: 1.5-2.0. Shrimp: 1.5-2.5. Catfish: 1.5-2.0. A lower FCR means more efficient feed conversion. High FCR increases cost of production and can indicate health or management issues.

Question 2

What is the maximum stocking density for fish in RAS?

Accepted Answer

In recirculating aquaculture systems (RAS), stocking density varies by species and system design. Salmon/trout: 50-100 kg/m3 with high aeration. Tilapia: 30-60 kg/m3. Shrimp: 200-500/m3. Stocking above capacity causes oxygen depletion, ammonia accumulation, aggression, and disease. Always calculate oxygen demand before increasing density.

Question 3

How do I calculate oxygen demand in a fish tank?

Accepted Answer

Oxygen consumption (mg O2/hour) = fish biomass (kg) x specific oxygen consumption rate (mg O2/kg/hour). At 20C, salmon consume roughly 200-400 mg O2/kg/hour at rest, more when feeding. Multiply by safety factor of 1.5-2.0 for aeration system design. Temperature increases sharply raise oxygen demand.

Question 4

Are these aquaculture tools free?

Accepted Answer

Yes - completely free, no sign-up required. Results export to CSV or PDF.

Free Aquaculture Tools & Calculators

Aquaculture calculators for healthy stock and profitable farms

Aquaculture Tools - FAQ