Aquarium Solutions Bacto-Surge Biological Sponge Filter Black XL Substrate Usage Notes: Always test magnesium

Usage Notes: Always test magnesium levels prior to use

Specifications (11

or freezer for up to six months

as well as deeper in the tank removing floating debris

Aquarium Solutions Bacto-Surge Biological Sponge Filter Black XL Substrate Usage Notes: Always test magnesiumHighly 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 clog Other uses: polishing filter for canister filter applications, hang on filter applications or uplift tubes of undergravel filters