Hikari HIK96040 2 x 4.7 in. Bacto-Surge Small Foam Filter
Bacto-Surge Biological Action Filters are air-driven sponge filters (air pump not included) which offer superior mechanical and biological filtration of your aquarium water. The highly porous sponge contains extreme surface area and thousands of microscopic pores where aerobic bacteria, hydrated with oxygenated water, can grow and flourish.
Other uses: polishing filter for canister filter applications, hang on filter applications or uplift tubes of undergravel filters.Features. Highly porous sponge maximizes bacterial action. Increased surface area offers maximum bacteria colonization. Soft sponge material is easily cleaned. Polyether foam for longer life. Uplift tube and air diffuser combination provide maximum lift and won't easily clogSpecifications. Capacity: 1.75 x 2 in.