How to use the feed result
The ration above is a starting point, not a fixed rule. Healthy fish in good water usually finish their feed within 10–15 minutes.
- Feed gone quickly and fish still searching: increase slightly (about 10%) next meal.
- Feed left after 15 minutes: reduce. Uneaten feed rots, raises ammonia and invites disease.
- Heavy rain, cold weather, foul water or fish gasping at the surface: cut feed by half or skip a day.
- Sick fish: reduce or pause feeding while you improve water quality.
How to find the average weight (sampling)
- Catch 10–20 fish at random, not just the biggest.
- Weigh a bucket with water, add the fish, weigh again. The difference is the total fish weight.
- Divide by the number of fish. Repeat every 7–10 days; the daily ration grows with the fish.
Feeding rate reference (% of body weight per day)
| Fish size | Catfish & Pangasius | Tilapia | Gourami |
|---|---|---|---|
| < 5 g | 8–10% | 8–10% | 5–7% |
| 5–20 g | 5–6% | 5–7% | 3–5% |
| 20–50 g | 4–5% | 4–5% | 3–5% |
| 50–100 g | 3–4% | 3–4% | 2–3% |
| > 100 g | 2–3% | 2–3% (> 250 g: 1.5–2%) | 1.5–3% |
General reference values commonly used in tropical pond culture. The recommendation on your feed bag and your water temperature take priority: fish eat much less in cool water.
What FCR is and why it matters
Feed conversion ratio (FCR) is how many kilograms of feed it takes to add one kilogram of fish. FCR = total feed ÷ (harvest weight − stocking weight). Example: 120 kg of feed and a 100 kg weight gain give an FCR of 1.2.
Feed is usually 60–70% of production cost, so small FCR differences matter: on one tonne of fish, FCR 1.0 versus 1.3 is 300 kg of feed.
| Species | Typical FCR (commercial pellets) |
|---|---|
| African catfish | 0.8–1.1 |
| Tilapia, Pangasius | 1.2–1.5 |
| Giant gourami | 1.5–2.0 |
Common causes of a high FCR
- Overfeeding and uneaten feed (the most common).
- Poor water quality: low oxygen means fish eat but don't grow.
- Sick or stressed fish, overstocking (see stocking density), or high mortality.
- Pellet size that doesn't match the fish's mouth.