Biospheres are hollow spheres made of plastic material with a large surface area that can attach a large number of nitrifying bacteria. There is no resistance when the water flows through, and the hollow structure can divide the water into small streams, crushing large pieces of dirt, and the filtering effect is good. The principle of the biochemical ball is to let the water flow through the internal tortuous space to prolong the time of the water flow, and the nitrifying bacteria attached to the internal multi-column structure can achieve the effect of biochemical filtration.