Phosphate-free preparation to safely reduce the pH level. Every influence on pH must be checked with a pH test. Contains a natural oak extract. The KH should be checked and adjusted to 4 – 8° dKH prior to use. (with JBL AquaDur). Before manipulating the pH-value, it is advisable to address the issue. There are 3 ways to lower the pH-value: by adding CO2 (carbon dioxide), by means of JBL pH-Minus or by using active peat (JBL TorMec activ). Of these three, peat has the weakest effect. It is always most important to determine the KH (carbonate hardness) which stabilizes the pH-value in advance. With a KH under 4 °dKH the pH-value is so unstable, that the slightest amounts of pH-Minus or CO2 can lead to serious problems.