The Filter-Max Pre-Filter filters the water before it reaches the main filter. It provides both mechanical and biological filtration. Aerobic bacteria colonize the sponge, providing a bacterial substrate to facilitate the nitrogen cycle.
An advantage of using the Filter-Max is it maintains the biological filtration when the main filter is changed or cleaned. It also prevents debris such as dead fish and plant material from clogging the intake by distributing the suction evenly down the length of the sponge. It prevents small or baby fish, anemones and invertebrates from being suctioned into the main filter.
The Filter-Max can be used with most outside power filters, canister filters, and power heads. It includes three adapters for use with various main filter intake tubes. It can be used in the vertical or horizontal position.