Why is it important? Timely control of water alkalinity and acidity is a key condition for growing many crops of adult plants. The pH level determines the efficiency of plant roots assimilation of all nutrients and elements in the hydroponic solution. Optimal pH level: from 5.5 to 7.5 units - measured using a pH meter, which is pre-calibrated in buffer solutions (solutions and device included) What to do if the pH is above / below normal ? If the measured values are exceeded, correctors (pH-UP) and (pH-DOWN) are used - these are special compounds that can affect the acidic and alkaline composition of water, thereby bringing these indicators back to normal.