pH Meters are instruments used to measure the acidity or basicity of a solution. A soil pH of 7 is neutral, a soil pH of less than 7 is acidic, and a soil pH greater than 7 is considered alkaline. The pH scale is logarithmic in nature, which means it represents a 10-fold difference for each unit change. Therefore, a soil pH of 5.0 is 10 times more acidic than soil pH of 6.0
It is very important to know the pH of a nutrient solution, since it determines how well plants will be able to take up this applied solution. Additionally, pesticides performs best at different pH ranges, hence the pH of the water to be used for pesticide application must be measure and adjust if necessary.