Ideally, your film developer and other chemicals should all be used at 68°F. In reality, temperatures can vary widely unless you have an expensive fluid control system installed in your darkroom.
Fortunately, we have found an easy Fahrenheit chart that works great.
| 64° | 66° | 68° | 70° | 72° | 75° | 77° | 80° |
|---|---|---|---|---|---|---|---|
| 5:00 | 4:30 | 4:00 | 3:30 | 3:15 | 2:30 | N/R | N/R |
| 5:30 | 5:00 | 4:30 | 4 | 3:45 | 3:00 | N/R | N/R |
| 6:00 | 5:30 | 5:00 | 4:30 | 4:00 | 3:15 | N/R | N/R |
| 6:30 | 6:00 | 5:30 | 5:00 | 4:30 | 3:30 | N/R | N/R |
| 7:15 | 6:30 | 6:00 | 5:30 | 5:00 | 4:00 | 3:45 | N/R |
| 8:00 | 7:15 | 6:30 | 6:00 | 5:15 | 4:30 | 4:00 | 3:30 |
| 8:45 | 7:45 | 7:00 | 6:30 | 5:45 | 5:00 | 4:30 | 3:45 |
| 9:15 | 8:15 | 7:30 | 6:45 | 6:00 | 5:15 | 4:45 | 4:00 |
| 9:45 | 8:45 | 8:00 | 7:15 | 6:30 | 5:30 | 5:00 | 4:15 |
| 10:30 | 9:30 | 8:30 | 7:45 | 6:30 | 6:00 | 5:30 | 4:45 |
| 11:15 | 10:00 | 9:00 | 8:00 | 7:15 | 6:15 | 5:45 | 5:00 |
| 11:45 | 10:30 | 9:30 | 8:30 | 7:45 | 6:30 | 6:00 | 5:15 |
| 12:30 | 11:15 | 10:00 | 9:00 | 8:00 | 7:00 | 6:15 | 5:30 |