To raise pH, we recommend using calcium carbonate and potassium carbonate (AquaUp), and either alternating between them or adding equal amounts of each at the same time. We prefer to use these carbonate compounds instead of hydroxide compounds (calcium hydroxide and potassium hydroxide) for several reasons. First, they add to the strength of our buffer. Second, they are not caustic and won’t burn your skin like the hydroxides will. Third, they are on the OMRI list of approved additives for organically certified production.