| Extremely acid | < 4.5 |
| Very strongly acid | 4.5 - 5.0 |
| Strongly acid | 5.0 - 5.5 |
| Moderately acid | 5.5 - 6.0 |
| Slightly acid | 6.0 - 6.5 |
| Neutral | 6.5 - 7.3 |
| Stlightly alkaline | 7.3 - 7.8 |
| Moderately alkaline | 7.8 - 8.5 |
| Strongly alkaline | 8.5 - 9.0 |
| Very Strongly alkaline | > 9.0 " |