Formulation with acidifying action. The product is to be used as pH corrective for hard waters employed for foliar nutrition and for agrochemicals applications. VIRACID improves nutrients absorption and efficacy of the active ingredients that in alkaline waters are considerably reduced. Adding VIRACID to the irrigation water brings to a drop of the pH to an optimal level and, colouring the solution differently as per its pH value, allows identification of the exact suitable dosage. In fact, in the beginning the solution becomes yellow, meaning that the pH is still too high; continuing with adding the product the pH reached is about 6, at this value the solution becomes red. The acidifying action of VIRACID ensures that irrigation systems are kept free of Calcium deposits. Pipes and nozzles remain clean and blockage-free. VIRACID can be applied also to provide high nutrition in Phosphorus and Nitrogen both in fertigation and in foliar application.