Freshwater – but friendly and safe. Reduces pH and KH values. Regulates carbonate hardness and pH level. Suitable for soft and slightly acidic water. Some fish species, such as cichlids and angelfish, are adapted to very soft water and must be bred under such conditions. However, due to the natural processes of photosynthesis, the water can sometimes have too high a carbonate hardness or pH level, even when other fish species are kept in the aquarium. pH and KH values are lowered and regulated immediately and precisely. This creates the right living conditions that keep the fish alive and healthy. Tip: Maintain a KH value of 4°dKH with sera pH/KH-minus and then add sera super Peat to the filter to maintain the tropical freshwater effect.