The main equipment of the sewage treatment system includes grills, aerators, submersible pumps and so on. In order to isolate coarse suspended particles and garbage, the grille is essential. For small systems, set up 1 fine grating can be, depending on the situation using 3-10mm gap. At the same time, taking into account the system slag is generally less, the grille can be used in a simple form, such as directly in the grille well to set up a fixed grille or can be lifted in the filter basket, regular manual slagging.