Ec and pH Management will prevent over fertilizing and nutrient lock out. You want to avoid these two problems. Ec management will prevent over fertilizing which you defiantly don't want to do as your plant will become sick and die. Over fertilizing will burn your roots and kill the root systems. Under fertilizing will cause the plant to loose its colour and vigour. Controlling pH Management will prevent Nutrient lock out. Nutrient lock out is where the plant will no longer take up the nutrients you are providing it.