Mills pH+ Mills pH+ works to stabilize and optimize the pH levels of your plant’s irrigation water throughout the growing cycle. This additive can be used to adjust pH levels throughout all stages of cultivation – keeping pH levels firmly between 5.5 -6.0 for hydro and 6.0-6.5 for soil. Ensuring you have the correct pH levels is essential to promoting rapid, vigorous growth and ensuring nutrients and soil are in desirable ratios. Optimizes the pH-value of your nutrition pH+ can be used to optimize the pH value of your nutrition at any stage of your grow. Optimizes the pH-value of the substrate The right pH ensures that your nutrients and soil are in perfect balance, to produce the best possible flowers. Highly concentrated Highly concentrated 50% potassium hydroxide solution for strong effect and longer use.