Water conditioner for species-appropriate, soft, and slightly acidic water. Reduces pH value and carbonate hardness (KH). Suitable for soft aquarium water. Supports the proper care of discus and angelfish. Helps combat acute ammonia poisoning. Enhances plant growth by releasing CO2. Package size: 250 ml, coverage: 1000 l. Some fish species, such as discus and angelfish, are adapted to very soft water and require this condition especially for breeding. Even when keeping other fish species, the water may have too high a carbonate hardness (KH) or the pH value may have risen too much due to natural metabolic processes. In these cases, sera pH/KH-minus works reliably and quickly. The pH value and KH are immediately and precisely lowered and regulated. This creates species-appropriate living conditions that significantly contribute to the vitality and well-being of the fish.