Nutrient lockout can happen to the soil when the pH level is outside of the 6-8 pH range. It can cause irregularities such as growth stunting, wilting and leaf spots. The best way to prevent it is to regularly check the pH level of your soil, as well as the pH level of the nutrients you are using. If your soil already has a low or high pH, the nutrients you are using may be throwing it out of range, so you may need to balance the pH levels in the nutrients with the liquid pH-up and pH-down controls. JUMP TO PH CONTROL