Figure 1
Combination index ranges for five antibiotics in mixtures in terms of toxicity to photosynthetic aquatic organisms proposed by Chou (33)
| Combination index range | Description |
|---|---|
| <0.1 | Very strong synergism |
| 0.10–0.30 | Strong synergism |
| 0.30–0.70 | Synergism |
| 0.70–0.85 | Moderate synergism |
| 0.85–0.90 | Slight synergism |
| 0.90–1.10 | Nearly additive |
| 1.10–1.20 | Slight antagonism |
| 1.20–1.45 | Moderate antagonism |
| 1.45–3.30 | Antagonism |
| 3.30–10 | Strong antagonism |
| >10 | Very strong antagonism |