Besides the normal requirements for freshwater tanks, it has to be mentioned that puffers have a very active metabolism. That means that they eat greedily and, therefore, incriminate the water a lot. Even barely populated puffer tanks should provide a strong, especially biological, filtration. Because of missing or low planting, a weekly partial water change of 30% is recommended to reduce mineral nutriments like nitrate. We already responded to the puffer‘s need of oxygen. It is indispensable to provide a very good supply of oxygen. A strong aquarium aerator is necessary, since the animals, particularly after extensive eating, are very oxygen-needy and can suffocate easily.