pH- 17% contains 17% Phosphoric Acid. It is meant to be added to water or nutrient mix when it is too alkaline to be used to water plants. Slowly add drops and stir your solution to make the mix more acidic and bring the pH level down to any range needed for your plants. Can be added to a reservoir to maintain pH levels of a storage solution or used upon every hand watering.

Optimum Hydroponix pH Up 1L 17%