Xtreme NP Reduction Bio Media is the most effective filtration used for the control of nitrates and phosphates within the aquarium ecosystem, while also providing a continuous bacterial food source for the health and well-being of your system. Best utilized with a reactor. Media should be kept fluidized for optimal results. Xtreme NP Reduction Bio Media cannot be overdosed, however, if your aquarium is high in nutrients, you may experience a brief baterial bloom. If this occurs, monitor and maintain an appropriate pH level. Xtreme NP Reduction Bio Media is ecologically friendly and totally biodegradable. Does not contain harmful PCL resins. Not manufactured in China.