Alkalinity and pH are two important factors in determining the suitability of water for irrigating plants.
Alkalinity is a measure of the water's ability to neutralize acidity.
The desirable range f or irrigation water is 0 to 100 ppm calcium carbonate. Levels between 30 and 60 ppm are considered optimum for most plants. Irrigation water tests should always include both pH and alkalinity tests. A pH test by itself is not an indication of alkalinity. This is important because high alkalinity exerts the most significant effects on growing medium fertility and plant nutrition.