Feed frequency is based on fish size and how quickly fish consume feed. When small trout are started on feed, they should be fed small amounts at frequent intervals. As fish grow larger, the frequency of daily feedings deceases. A general rule of thumb is to feed 1% of body weight per feeding and to adjust feed frequency to obtain the desired feeding percentage to ensure all fish have access to feed. Thus, if fish are being fed 4% of body weight per day, they should be fed four feedings per day. See the following table for recommended feedings per day for rainbow trout.
| Fish size (number/pound) | Feed sizes | Feedings/Day |
|---|---|---|
| 2,500 – 2,000 | “Starter” | 8-10 |
| 2,000 – 800 | #1 Granule | 8 |
| 800 – 250 | #2 Granule | 6 |
| 250 – 100 | #3 Granule | 4 |
| 100 – 30 | #4 Granule | 3 |
| 30 – 15 | 3/32 Pellet | 3 |
| 15 – 9 | 1/8 Pellet | 2-3 |
| 9 – 3 | 5/32 Pellet | 1-2 |
| 3 – 1 | 3/16 Pellet | 1 |
| >1 | 3/16 Pellet | 1 |
Hinshaw, J.M. 1990. Trout Production: Feeds and Feeding Methods. SRAC Publication No. 223.