Univ. of Mass. floriculture professor Doug Cox said growers who only do in-house tests on their water for pH measurement, are only do half the job. Cox said a pH test by itself is useful, but it is not an indicator alkalinity. Water tests should include both pH and alkalinity.
Cox said water with a high alkalinity (i.e., high levels of bicarbonates or carbonates) always has a pH value of 7 or higher. Water with a high pH doesn’t necessarily have a high alkalinity.
In Massachusetts, Cox said, it is common for irrigation water to have a high pH (7-8) and low alkalinity (less than 100 parts per million calcium carbonate). In some cases, both the pH and alkalinity can be high.
Pictured: Water tests should include both pH and alkalinity. A pH test by itself is useful, but it does not provide a measurement of alkalinity. Water with a high pH doesn’t necessarily have a high alkalinity.