Filtration, generally, is a physical method/procedure for separating or removing solid particles from liquids or gases. Various methods and instruments can be used to carry out filtration. Unlike sieving, filtration involves many layers of the filters through which the solid particles are unable to pass. Depending upon the size of particle appropriate pore size of the filter is decided. When biological elements are used to not only filter out but even degrade the solids, it is referred to as Biofiltration. For the removal of metal solids, magnets may be used. The traditional way of filtration involves using filter papers, but this process is too slow and filter papers may get clogged every now and then, adding to the delay and troubles. Vacuum or suction filtration, which is yet another type of filtration, solves this problem by drawing liquid through the filter layers via the air pressure. A typical filtration unit in the laboratory has the same principle and comprises of a top part made of glass through which the liquid is poured. This part also contains the filter in it. Filters can be changed whenever necessary. Beneath this is the flask which collects the filtrate. The flask also has a connection point through which a pipe is connected to the vacuum motor or vacuum pump. These units can also be purchased/ ordered separately.