What is pH?
pH stands for potential hydrogen and is a measure of a solutions alkalinity represented on a scale from 0-14. A pH measure of 7 is considered neutral. A solution is considered basic if it measures between 7 and 14, while a solution measuring 0 to 7 is considered acidic. The pH of a nutrient solution is very important in hydroponics because it plays a big role in which macro and micro nutrients a plant can uptake.
What is the correct pH for my grow medium?
Generally speaking, a rootzone pH of 6.0 to 6.5 in soil will be favorable for most plants. In coco or hydroponic applications, use a slightly lower pH of 5.7-6.0.