Some fish species (e.g. discus and angelfish) are adapted to very soft water and require these conditions in particular for reproducing. However, the water can provide too high carbonate hardness (KH), or the pH may have risen too strongly due to natural metabolism processes, also when keeping other fish species. In these cases, sera pH/KH-minus provides reliable and quick support. The pH value and the KH are immediately and precisely lowered and regulated. This creates appropriate keeping conditions that considerably contribute to the vitality and the fish doing well.sera pH/KH-minus+ lowers pH and KH+ adjusts the carbonate hardness+ regulates the pH value+ for appropriate soft and slightly acidic waterRecommended dosage sera pH/KH-minusFor lowering the carbonate hardness (KH) by approx. 1dKH daily, add 5 ml sera pH/KH-minus for every 5.3 US gal. (20 l) of water.- for lowering KH and pH- for immediate help in case of acute intoxications by ammonia- for preparing the application of se