pH- Grow - pH ReducerpH Regulator Reducing pH for Max Yield! pH is designed specifically to reduce the pH level during the Grow phase. pH Grow uses Nitric Acid as its main ingredient. Usage Use pH Grow to balance your pH after adding the nutrients only in VEG Keep your pH between 5. 8 6. 5 to make sure all the elements get taken up by the roots You only need a couple drops per gallon to lower your pH to the desired levels How does pH Grow work?