本发明是当锦鲤、金鱼、热带鱼等淡水鱼类饲养用水的水质不良时,将其改良成为适于淡水鱼类饲养的水质改善方法。淡水鱼类饲养中,当其所使用水的硬水物质过多,或含有金属和氨类等物质,或是酸性过强时,水质就会不适于鱼类的饲养。本发明就是为了防止和改善这种不适于淡水鱼类饲养的恶化水质而创立的一种方法,以使 According to the present invention, when the water quality of freshwater fish breeding water such as koi carp, goldfish and tropical fish is poor, it is improved to a water quality improvement method suitable for raising freshwater fish. In freshwater fish feeding, water quality is not suitable for keeping fish when there are too many hard water substances in the water used, or substances such as metals and ammonia, or when the acidity is too high. The present invention is directed to preventing and ameliorating such a deteriorated water quality which is not suitable for rearing freshwater fish, so that