Ultra pH down adjustment Gold Label Ultra pH- is an universal acid for adjusting the pH levels of nutrient solutions. It contains a balanced mix of phosphoric acid, nitric acid and sulphuric acid. Add last to your nutrients solution, reduce pH carefully in small steps and stir well before measuring. Use Ultra pH- in the vegetative and flowering period. Recommended for all type of substrates and nutrient schedules. Shake well before use. Keep away from children Store in dry and concealed place.