<4.0

4.0 - 4.9

5.0 - 5.4

5.5 - 5.9

6.0 - 7.5

7.6 - 8.4

8.5 - 9.4

>9.5

Ext. acid

Very acid

acid

Light. acid

Neutral

Light. Alkaline

Alkaline

Very alkaline