Concentrated and effective KH buffer supplement. KH / Alk + Marine raises the carbon hardness / alkalinity and stabilizes the pH value. The carbon hardness should be in a range of 6-9° KH. A dosing cap (10 ml) from KH / Alk + Marine = 40 härteliter. In other words, 1 dosing cap per 40 L raises the KH value with ± 1° KH.