The good news is that most water samples we tested did not reveal serious problems. Clogging of microirrigation systems is also more likely at high pH. Depending largely on the alkalinity, pH can change rapidly, especially in a pond or other water source with much biological activity. Because it can change quickly, pH is best measured on site. However, litmus paper strips and hand-held meters used on site often are less accurate than testing equipment that would be used at a laboratory. 118 Alkalinity Alkalinity is a measure of a water's ability to buffer or stabilize pH. While pH and alkalinity are related, they are not the same thing.
Alkalinity is important in container production, much less so in field production.
As the container media pH rises, the availability of micronutrients decreases and plants may turn yellow. Soluble salts can come from fertilizers or deicing salts, but a body of water also can become salty over time through evaporation. As water evaporates or is taken up by roots, the salts remain behind in soil or media and accumulate. Watch soluble salts levels in water recycling systems or any body of water receiving runoff. Chloride, sodium and sulfate are ions that contribute to high soluble salts, but also may have specific toxic effects on plants.