With this mix of phosphorus, nitric and organic citric acid you can adjust the PH value of the nutrient solution downwards. It is important that you try to maintain a PH value between 5.5 and 6.2. The PH value of the nutrient solution largely determines the absorption of certain elements by the plant. The phosphorus and nitric acid ensure a rapid decrease of the PH value while the citric acid provides stabilization. Unlike many PH-lowering agents, it has no influence on the nitrogen (N) and potassium (K) levels in the solution.